-Added ability to save playlist as remote playlist link rather than storing it in database.

-Added LeakCanary as part of debug build.
-Modified bookmark list to show both remote and local playlists.
-Removed ability to save channel items as local playlist, in favor of subscribe.

app/src/main/java/org/schabi/newpipe/App.java

@@ -1,12 +1,9 @@
 package org.schabi.newpipe;
 
-import android.app.AlarmManager;
 import android.app.Application;
 import android.app.NotificationChannel;
 import android.app.NotificationManager;
-import android.app.PendingIntent;
 import android.content.Context;
-import android.content.Intent;
 import android.os.Build;
 import android.util.Log;