Add notification to warn user about the unlock state

Clean up code

Add minor changes

app/src/main/java/com/beemdevelopment/aegis/services/NotificationService.java

@@ -0,0 +1,61 @@
+package com.beemdevelopment.aegis.services;
+
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Intent;
+import android.os.IBinder;
+
+import androidx.annotation.Nullable;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.NotificationManagerCompat;
+
+import com.beemdevelopment.aegis.AegisApplication;
+import com.beemdevelopment.aegis.R;
+
+public class NotificationService extends Service {
+    public static final int DATABASE_UNLOCKED_ID = 1;
+
+    private static final String CODE_LOCK_STATUS_ID = "lock_status_channel";
+    private static final String CODE_LOCK_DATABASE_ACTION = "lock_database";
+
+    public NotificationService() {
+
+    }
+
+    @Override
+    public int onStartCommand(Intent intent,int flags, int startId){
+        super.onStartCommand(intent, flags, startId);
+
+        serviceMethod();
+        return Service.START_STICKY;
+    }
+
+    public void serviceMethod() {
+        Intent intentAction = new Intent(CODE_LOCK_DATABASE_ACTION);
+        PendingIntent lockDatabaseIntent = PendingIntent.getBroadcast(this,1,intentAction, 0);
+        NotificationCompat.Builder builder = new NotificationCompat.Builder(this,  CODE_LOCK_STATUS_ID)
+                .setSmallIcon(R.drawable.ic_fingerprint_black_24dp)
+                .setContentTitle(getString(R.string.app_name_full))
+                .setContentText(getString(R.string.vault_unlocked_state))
+                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
+                .setOngoing(true)
+                .setContentIntent(lockDatabaseIntent);
+
+        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
+        notificationManager.notify(DATABASE_UNLOCKED_ID, builder.build());
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+
+        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
+        notificationManager.cancel(DATABASE_UNLOCKED_ID);
+    }
+
+    @Nullable
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+}