-Fixed main player paused video not abandoning audio focus after navigating away from activity during interruption, when resume on focus regain is enabled.

-Separated onPause and onPlay functions from onPlayPause.
-Renamed onVideoPlayPause to onPlayPause.

app/src/main/java/org/schabi/newpipe/player/BackgroundPlayer.java

@@ -486,7 +486,7 @@ public final class BackgroundPlayer extends Service {
                     onClose();
                     break;
                 case ACTION_PLAY_PAUSE:
-                    onVideoPlayPause();
+                    onPlayPause();
                     break;
                 case ACTION_REPEAT:
                     onRepeatClicked();

app/src/main/java/org/schabi/newpipe/player/BasePlayer.java

@@ -392,7 +392,7 @@ public abstract class BasePlayer implements
         if (intent == null || intent.getAction() == null) return;
         switch (intent.getAction()) {
             case AudioManager.ACTION_AUDIO_BECOMING_NOISY:
-                if (isPlaying()) onVideoPlayPause();
+                onPause();
                 break;
         }
     }
@@ -948,14 +948,11 @@ public abstract class BasePlayer implements
         changeState(playWhenReady ? STATE_PLAYING : STATE_PAUSED);
     }
 
-    public void onVideoPlayPause() {
-        if (DEBUG) Log.d(TAG, "onVideoPlayPause() called");
+    public void onPlay() {
+        if (DEBUG) Log.d(TAG, "onPlay() called");
+        if (audioReactor == null || playQueue == null || simpleExoPlayer == null) return;
 
-        if (!isPlaying()) {
         audioReactor.requestAudioFocus();
-        } else {
-            audioReactor.abandonAudioFocus();
-        }
 
         if (getCurrentState() == STATE_COMPLETED) {
             if (playQueue.getIndex() == 0) {
@@ -965,7 +962,25 @@ public abstract class BasePlayer implements
             }
         }
 
-        simpleExoPlayer.setPlayWhenReady(!isPlaying());
+        simpleExoPlayer.setPlayWhenReady(true);
+    }
+
+    public void onPause() {
+        if (DEBUG) Log.d(TAG, "onPause() called");
+        if (audioReactor == null || simpleExoPlayer == null) return;
+
+        audioReactor.abandonAudioFocus();
+        simpleExoPlayer.setPlayWhenReady(false);
+    }
+
+    public void onPlayPause() {
+        if (DEBUG) Log.d(TAG, "onPlayPause() called");
+
+        if (!isPlaying()) {
+            onPlay();
+        } else {
+            onPause();
+        }
     }
 
     public void onFastRewind() {

app/src/main/java/org/schabi/newpipe/player/MainVideoPlayer.java

@@ -49,7 +49,6 @@ import android.widget.SeekBar;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.ui.AspectRatioFrameLayout;
 import com.google.android.exoplayer2.ui.SubtitleView;
@@ -153,7 +152,7 @@ public final class MainVideoPlayer extends AppCompatActivity
         if (DEBUG) Log.d(TAG, "onResume() called");
         if (playerImpl.getPlayer() != null && activityPaused && playerImpl.wasPlaying()
                 && !playerImpl.isPlaying()) {
-            playerImpl.onVideoPlayPause();
+            playerImpl.onPlay();
         }
         activityPaused = false;
 
@@ -188,7 +187,7 @@ public final class MainVideoPlayer extends AppCompatActivity
 
         if (playerImpl != null && playerImpl.getPlayer() != null && !activityPaused) {
             playerImpl.wasPlaying = playerImpl.isPlaying();
-            if (playerImpl.isPlaying()) playerImpl.onVideoPlayPause();
+            playerImpl.onPause();
         }
         activityPaused = true;
     }
@@ -563,7 +562,7 @@ public final class MainVideoPlayer extends AppCompatActivity
         public void onClick(View v) {
             super.onClick(v);
             if (v.getId() == playPauseButton.getId()) {
-                onVideoPlayPause();
+                onPlayPause();
 
             } else if (v.getId() == playPreviousButton.getId()) {
                 onPlayPrevious();

app/src/main/java/org/schabi/newpipe/player/PopupVideoPlayer.java

@@ -618,7 +618,7 @@ public final class PopupVideoPlayer extends Service {
                     onClose();
                     break;
                 case ACTION_PLAY_PAUSE:
-                    onVideoPlayPause();
+                    onPlayPause();
                     break;
                 case ACTION_REPEAT:
                     onRepeatClicked();
@@ -731,7 +731,7 @@ public final class PopupVideoPlayer extends Service {
         public boolean onSingleTapConfirmed(MotionEvent e) {
             if (DEBUG) Log.d(TAG, "onSingleTapConfirmed() called with: e = [" + e + "]");
             if (playerImpl == null || playerImpl.getPlayer() == null) return false;
-            playerImpl.onVideoPlayPause();
+            playerImpl.onPlayPause();
             return true;
         }
 

app/src/main/java/org/schabi/newpipe/player/ServicePlayerActivity.java

@@ -424,7 +424,7 @@ public abstract class ServicePlayerActivity extends AppCompatActivity
             player.onPlayPrevious();
 
         } else if (view.getId() == playPauseButton.getId()) {
-            player.onVideoPlayPause();
+            player.onPlayPause();
 
         } else if (view.getId() == forwardButton.getId()) {
             player.onPlayNext();

app/src/main/java/org/schabi/newpipe/player/playback/BasePlayerMediaSession.java

@@ -62,12 +62,12 @@ public class BasePlayerMediaSession implements MediaSessionCallback {
 
     @Override
     public void onPlay() {
-        if (!player.isPlaying()) player.onVideoPlayPause();
+        player.onPlay();
     }
 
     @Override
     public void onPause() {
-        if (player.isPlaying()) player.onVideoPlayPause();
+        player.onPause();
     }
 
     @Override