Update Javadoc for openVideoPlayerAutoFullscreen

Author: Y2kz

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

@@ -1135,12 +1135,15 @@ public void openVideoPlayer(final boolean directlyFullscreenIfApplicable) {
     }
 
     /**
-     * If the option to start directly fullscreen is enabled, calls
-     * {@link #openVideoPlayer(boolean)} with {@code directlyFullscreenIfApplicable = true}, so that
-     * if the user is not already in landscape and he has screen orientation locked the activity
-     * rotates and fullscreen starts. Otherwise, if the option to start directly fullscreen is
-     * disabled, calls {@link #openVideoPlayer(boolean)} with {@code directlyFullscreenIfApplicable
-     * = false}, hence preventing it from going directly fullscreen.
+     * If the option to start directly fullscreen is enabled, or if {@code forceFullscreen} is
+     * {@code true} (e.g. when switching from popup player to main player with a different video),
+     * calls {@link #openVideoPlayer(boolean)} with {@code directlyFullscreenIfApplicable = true},
+     * so that if the user is not already in landscape and he has screen orientation locked the
+     * activity rotates and fullscreen starts. Otherwise, if the option to start directly fullscreen
+     * is disabled and {@code forceFullscreen} is {@code false}, calls
+     * {@link #openVideoPlayer(boolean)} with {@code directlyFullscreenIfApplicable = false},
+     * hence preventing it from going directly fullscreen.
+     * {@code forceFullscreen} is reset to {@code false} after this call.
      */
     public void openVideoPlayerAutoFullscreen() {
         openVideoPlayer(forceFullscreen