Attempt to invoke virtual method 'void android.os.Messenger.send(android.os.Message)' on a null object reference

I am trying to implement a RemoteBound Service using Messenger and Handler. When Client and Service are in Same Application things works. However when they are put in different Applications, Client is not able to Bind to Service.

RemoteService.java

public class RemoteService extends Service {

    private final IBinder iBinder = new Messenger(new IncomingHandler(this)).getBinder();

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return iBinder;
    }

}

IncomingHandler.java

public class IncomingHandler extends Handler {

    private RemoteService remoteService;

    public IncomingHandler(Context context)
    {
        this.remoteService = (RemoteService)context;
    }

    public RemoteService getService()
    {
        return this.remoteService;
    }

    @Override
    public void handleMessage(@NonNull Message msg) {
        try {
            msg.replyTo.send(getCurrentTime(msg));
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

    public Message getCurrentTime(Message msg){
        SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss MM/dd/yyyy", Locale.US);
        Message resp = Message.obtain();
        Bundle bResp = new Bundle();
        bResp.putString("respData", msg.getData().getString("MyString") + " : " +(dateFormat.format(new Date())).toString());
        resp.setData(bResp);
        return resp;
    }
}

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.remoteservicesetup">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.RemoteServiceSetUp">

        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


        <service
            android:name=".RemoteService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.example.remoteservicesetup.StartSampleService" />
            </intent-filter>
        </service>
    </application>

</manifest>

I am trying to Bind from the Client using the Below Code with onCreate() of MainActivity: Intent intent = new Intent("com.example.remoteservicesetup.StartSampleService"); intent.setPackage("com.example.remoteservicesetup"); bindService(intent,serviceConnector, Context.BIND_AUTO_CREATE);

Service Connector in Client been implemented as below:

public class ServiceConnector implements ServiceConnection {

    private Messenger messenger;

    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            this.messenger = new Messenger(iBinder);
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {
        this.messenger = null;
    }

    public Messenger getMessenger(){
        return this.messenger;
    }
}