Add following dependency to build.gradle:

implementation 'com.google.code.gson:gson:2.11.0'

Or download the JAR file from Maven by clicking a release and finding the .jar file.

Replace 2.8.7 with the latest version from Maven.

Visit the GitHub repo for documentation and more.

Open your project. Go to File -> Project Structure... Click on app in the Modules section and switch to the Dependencies tab. Click on the plus icon in the top right corner and select Library dependency. Select the entry for the GSON library from the list and hit OK twice. (Note: the search bar didn't work for me)

Then you are able to use the library just like you described in your question:
import com.google.gson.Gson;

Note that after adding the library your project will do a gradle sync which may take a couple of minutes.

I remembered how to do this really quickly. You have to go to File -> Project Structure. Then click the Libraries tab and the green plus. Once clicked select from Maven and then search GSON and find the correct GSON version you want to use from the menu and then GSON dependency will work.

I faced the same issue. I just added a single line as shown below in my build.gradle dependencies (without adding any jar in project structure) and it worked for me.

dependencies {
    compile 'com.google.code.gson:gson:2.2.+'
    compile 'com.android.support:support-v4:13.0.+'
    compile 'com.android.support:appcompat-v7:18.0.+'
}

Along with above, I found few more things which are required for this to work.

1. Make sure you have android:targetSdkVersion="18" in AndroidManifest.xml file.

   <uses-sdk
       android:minSdkVersion="10"
       android:targetSdkVersion="18" />
   

2. Make sure you have targetSdkVersion 18 in build.gradle file.

   defaultConfig {
       minSdkVersion 10
       targetSdkVersion 18
   }
   

3. Make sure you are connected to internet; so that jars will be downloaded from online central maven repository.

In app/build.gradle:

 dependencies {
    implementation 'com.google.code.gson:gson:2.11.0'
}