First try this

<style name="CustomAppTheme" parent="AppTheme">
    <item name="android:windowContentOverlay">@null</item>
</style>

If above solution does not work then do the following in the activity:

ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
    actionBar.setElevation(0);
}

First you need to add GSON dependency (ref)

compile 'com.google.code.gson:gson:2.2.4'

Writing object to shared preference

SharedPreferences sharedPref =  getApplicationContext().getSharedPreferences("com.example.myapp.PREFERENCE_FILE_KEY",Context.MODE_PRIVATE);
	
SharedPreferences.Editor editor = sharedPref.edit();

Gson gson = new Gson();

String jsonMyObject = gson.toJson(myObject);

editor.putInt("myObject", jsonMyObject );

editor.commit()

Reading Object from shared preference

SharedPreferences sharedPref =  getApplicationContext().getSharedPreferences("com.example.myapp.PREFERENCE_FILE_KEY",Context.MODE_PRIVATE);
	
Gson gson = new Gson();

String jsonMyObject= mSharedPreferences.getString("myObject", "");

myObject =  gson.fromJson(jsonMyObject, MyObject.class);

Saving List of objects in to shared preference

ArrayList<userModel> userList= new ArrayList<>();

userList.add(new userModel("Jos", "Kuriya"));
userList.add(new userModel("Kiran", "Pnr"));


Gson gson = new GsonBuilder().create();
JsonArray userJsonArray = gson.toJsonTree(userList).getAsJsonArray();


//Adding data to shared preference 
SharedPreferences.Editor editor = mSharedPref.edit();
editor.putString("MyUsers", userJsonArray + "");
editor.commit();



//Retrieving data from shared preference
String jsonPreferences = mSharedPref.getString("MyUsers", "");
Type type = new TypeToken<ArrayList<userModel>>() {}.getType();
ArrayList<userModel> dataFromSharedPref = gson.fromJson(jsonPreferences, type);

Google drive api does not sync immediately, That is why the deleted folders are still showing, so you have to force google drive to sync using requestSync()

A sample snippet

    private MetadataBuffer getGoogleFolders(){

        Drive.DriveApi.requestSync(mGoogleApiClient).await(); //Asynchronous request 

        CustomPropertyKey customPropertyKey = new CustomPropertyKey("App", CustomPropertyKey.PRIVATE);

        Query query = new Query.Builder().addFilter(Filters.and(
                Filters.eq(SearchableField.TITLE, "My folder"),
                Filters.eq(SearchableField.TRASHED, false),
                Filters.eq(customPropertyKey, "sampleApp"))).build();

        DriveApi.MetadataBufferResult foldersResult = Drive.DriveApi.query(mGoogleApiClient, query).await();

        if (!foldersResult.getStatus().isSuccess()) {
            Log.i(TAG,"Problem while retrieving results");
            return null;
        }

        MetadataBuffer result = foldersResult.getMetadataBuffer();

        Log.i(TAG, "total result " +  result.getCount());
        
        return result;
    }

OR

//Synchronous request 
Drive.DriveApi.requestSync(mClient).setResultCallback(new ResultCallback<Status>() {
            @Override
            public void onResult(@NonNull Status status) {

                //search query performs here 

            }
        });

1. Open your project explorer (this folder structure will not visible in Android explorer)
2. Create a new directory inside res folder name this new directory “layouts”. (This can be whatever you want)
3. create directory tree inside layouts folder (in my example i have created gallery inside layout and values, home ->layout and values, payment ->layout)
4. move your xml files into desired directory (inside layout folder) and delete the old layout folder

5. Add the following code in gradle file (app/build.gradle)

android {
    - - - - - - - - -
    - - - - - - - - -
    - - - - - - - - -

    sourceSets {
        main {
            res.srcDirs =
                    [
                            'src/main/res',
                            'src/main/res/layouts',
                            'src/main/res/layouts/gallery',
                            'src/main/res/layouts/home',
                            'src/main/res/layouts/paymet'
                    ]
        }
    }
 - - - - - - - - 

 - - - - - - - - 
}

Intent Service Class sample

public class MyIntentService extends IntentService {

    public static final String Somevariables = "somevalue";

    public MyIntentService() {

        super(MyIntentService.class.getName()); // you can give any string but it is good practice to giving classname
    }

    @Override
    public void onCreate() {
        super.onCreate();
        //--some code --
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        
        //you can retrive intent extras
        String msg = intent.getStringExtra(EXTRA_KEY);

        //--actual backgroung code gos here  --
    }
}

Add service in manifest also

<service android:name=".MyIntentService"/>

ref: https://developer.android.com/training/run-background-service/create-service.html

Getting application specific shared preference object

SharedPreferences sharedPref =  getApplicationContext().getSharedPreferences("com.example.myapp.PREFERENCE_FILE_KEY",Context.MODE_PRIVATE);

Getting activity specific shared preference object

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);

Write to Shared Preferences

SharedPreferences.Editor editor = sharedPref.edit();
//editor.putInt(getString(R.string.saved_high_score), newHighScore);
editor.putInt("HIGHSCORE", newHighScore);
editor.commit();

Read from Shared Preferences

//int highScore = sharedPref.getInt(getString(R.string.saved_high_score), defaultValue);

int highScore = sharedPref.getInt("HIGHSCORE", defaultValue);

ref: https://developer.android.com/training/basics/data-storage/shared-preferences.html#WriteSharedPreference