Fixed background playback behind notification center.

RCTVideo.m

@@ -63,6 +63,11 @@ static NSString *const playbackBufferEmptyKeyPath = @"playbackBufferEmpty";
                                                  name:UIApplicationWillResignActiveNotification
                                                object:nil];
 
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(applicationDidEnterBackground:)
+                                                 name:UIApplicationDidEnterBackgroundNotification
+                                               object:nil];
+
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(applicationWillEnterForeground:)
                                                  name:UIApplicationWillEnterForegroundNotification
@@ -118,13 +123,18 @@ static NSString *const playbackBufferEmptyKeyPath = @"playbackBufferEmpty";
 #pragma mark - App lifecycle handlers
 
 - (void)applicationWillResignActive:(NSNotification *)notification
+{
+  if (!_paused && !_playInBackground) {
+    [_player pause];
+    [_player setRate:0.0];
+  }
+}
+
+- (void)applicationDidEnterBackground:(NSNotification *)notification
 {
     if (_playInBackground) {
         // Needed to play sound in background. See https://developer.apple.com/library/ios/qa/qa1668/_index.html
         [_playerLayer setPlayer:nil];
-  } else if (!_paused) {
-    [_player pause];
-    [_player setRate:0.0];
     }
 }