In 2019 Best Offical Solution in Kotlin

Google API Client/FusedLocationApi are deprecated and Location Manager is not useful at all. So Google prefer Fused Location Provider Using the Google Play services location APIs "FusedLocationProviderClient" is used to get location and its better way for battery saving and accuracy

Here is sample code in kotlin to get the last known location /one-time location( equivalent to the current location)

 // declare a global variable of FusedLocationProviderClient
    private lateinit var fusedLocationClient: FusedLocationProviderClient

// in onCreate() initialize FusedLocationProviderClient
    fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)

 /**
     * call this method for receive location
     * get location and give callback when successfully retrieve
     * function itself check location permission before access related methods
     *
     */
    fun getLastKnownLocation() {
            fusedLocationClient.lastLocation
                .addOnSuccessListener { location->
                    if (location != null) {
                       // use your location object
                        // get latitude , longitude and other info from this
                    }

                }

    }

If your app can continuously track the location then you have to receive Receive location updates

Check the sample for that in kotlin

// declare a global variable FusedLocationProviderClient
        private lateinit var fusedLocationClient: FusedLocationProviderClient

    // in onCreate() initialize FusedLocationProviderClient
        fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)


      // globally declare LocationRequest
        private lateinit var locationRequest: LocationRequest

        // globally declare LocationCallback    
        private lateinit var locationCallback: LocationCallback


        /**
         * call this method in onCreate
         * onLocationResult call when location is changed 
         */
        private fun getLocationUpdates()
        {

                fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)
                locationRequest = LocationRequest()
                locationRequest.interval = 50000
                locationRequest.fastestInterval = 50000
                locationRequest.smallestDisplacement = 170f // 170 m = 0.1 mile
                locationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY //set according to your app function
                locationCallback = object : LocationCallback() {
                    override fun onLocationResult(locationResult: LocationResult?) {
                        locationResult ?: return

                        if (locationResult.locations.isNotEmpty()) {
                            // get latest location 
                            val location =
                                locationResult.lastLocation
                            // use your location object
                            // get latitude , longitude and other info from this
                        }


                    }
                }
        }

        //start location updates
        private fun startLocationUpdates() {
            fusedLocationClient.requestLocationUpdates(
                locationRequest,
                locationCallback,
                null /* Looper */
            )
        }

        // stop location updates
        private fun stopLocationUpdates() {
            fusedLocationClient.removeLocationUpdates(locationCallback)
        }

        // stop receiving location update when activity not visible/foreground
        override fun onPause() {
            super.onPause()
            stopLocationUpdates()
        }

        // start receiving location update when activity  visible/foreground
        override fun onResume() {
            super.onResume()
            startLocationUpdates()
        }

Make sure you take care about Mainfaist permission and runtime permission for location

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

and for Gradle add this

implementation 'com.google.android.gms:play-services-location:17.0.0'

For more details follow these official documents

https://developer.android.com/training/location/retrieve-current

https://developer.android.com/training/location/receive-location-updates

https://developers.google.com/android/reference/com/google/android/gms/location/FusedLocationProviderClient

So here's how you can get your current location. I am skipping the permission part as you can do that yourself.

private fun isLocationEnabled(): Boolean {
        val locationManager: LocationManager =
            getSystemService(Context.LOCATION_SERVICE) as LocationManager
        return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) || locationManager.isProviderEnabled(
            LocationManager.NETWORK_PROVIDER
        )
    }

 private fun getLastLocation() {
        if (isLocationEnabled()) {
           fusedLocationClient.lastLocation.addOnCompleteListener(this) { task ->
                val location: Location? = task.result
                if (location != null) {
                    //use the location latitude and logitude as per your use.
                    val latitude = location.latitude
                    val longitude = location.longitude
                }
            }
        }

The last comment (Jan 28) makes this question clear enough to answer:

1. A lat,lng location is already available, that is the starting point.
2. The goal is to obtain the the... a street address.
3. Currently this is done using geocoder.getFromLocation(latitute,longitude,1)
4. The problem is that this method is unstable and does not work sometimes.
5. The question is then: Is there anything else that I can use?

And the answer is: yes, with caveats.

First, please note that geocoder.getFromLocation() is provided by Android, for free but without guarantees:

Warning: Geocoding services may provide no guarantees on availability or accuracy. Results are a best guess, and are not guaranteed to be meaningful or correct. Do not use this API for any safety-critical or regulatory compliance purpose.

Since your concern seems to be the reliability of this service, a better solution may be provided by the Google Maps Platform Geocoding API, which does offer certain guarantees of latency and availability, as it is one of the Google Maps Platform Core Services.

The first caveat of this solution is that it is not entirely free of charge, see here How the Geocoding API is billed and consider what the cost would be for based on your user base and how often a latlng needs to be converted to an address. Make sure to restrict your API keys and optimize your usage.

The second caveat, which you might even like, is that this API doesn't return just one address, it tends to return a few. You can try this out using the Geocoder Tool at https://developers.google.com/maps/documentation/utils/geocoder (click on the map and it will reverse geocode that point).