Another part of UI improvements for Android TV

- focus will be hidden right after start of a video; fullscreen works like this too
- back button will not needed to be pressed one more time like before
- prev & next buttons for playqueue will be hidden with play/pause button before video be ready to play

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -2158,8 +2158,9 @@ public class VideoDetailFragment
     /**
      * That's for Android TV support. Move focus from main fragment to the player or back
      * based on what is currently selected
+     *
      * @param toMain if true than the main fragment will be focused or the player otherwise
-     * */
+     */
     private void moveFocusToMainFragment(final boolean toMain) {
         final ViewGroup mainFragment = requireActivity().findViewById(R.id.fragment_holder);
         // Hamburger button steels a focus even under bottomSheet

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

@@ -163,6 +163,9 @@ public final class MainPlayer extends Service {
             // from one stream to a new stream not smooth
             playerImpl.getPlayer().stop(false);
             playerImpl.setRecovery();
+            // Android TV will handle back button in case controls will be visible
+            // (one more additional unneeded click while the player is hidden)
+            playerImpl.hideControls(0, 0);
             // Notification shows information about old stream but if a user selects
             // a stream from backStack it's not actual anymore
             // So we should hide the notification at all.

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

@@ -253,9 +253,12 @@ public class VideoPlayerImpl extends VideoPlayer
             getRootView().setVisibility(View.VISIBLE);
             initPopup();
             initPopupCloseOverlay();
+            playPauseButton.requestFocus();
         } else {
             getRootView().setVisibility(View.VISIBLE);
             initVideoPlayer();
+            // Android TV: without it focus will frame the whole player
+            playPauseButton.requestFocus();
         }
 
         onPlay();
@@ -1057,10 +1060,10 @@ public class VideoPlayerImpl extends VideoPlayer
 
     private void animatePlayButtons(final boolean show, final int duration) {
         animateView(playPauseButton, AnimationUtils.Type.SCALE_AND_ALPHA, show, duration);
-        if (playQueue.getIndex() > 0) {
+        if (playQueue.getIndex() > 0 || !show) {
             animateView(playPreviousButton, AnimationUtils.Type.SCALE_AND_ALPHA, show, duration);
         }
-        if (playQueue.getIndex() + 1 < playQueue.getStreams().size()) {
+        if (playQueue.getIndex() + 1 < playQueue.getStreams().size() || !show) {
             animateView(playNextButton, AnimationUtils.Type.SCALE_AND_ALPHA, show, duration);
         }