Move View Controller retrieval to external UIView category

RCTVideo.m

@@ -574,26 +574,6 @@ static NSString *const playbackBufferEmptyKeyPath = @"playbackBufferEmpty";
   }
 }
 
-#pragma mark - View Controller retrieval
-
-// http://stackoverflow.com/questions/1340434/get-to-uiviewcontroller-from-uiview/2596519
-
-- (UIViewController *) firstAvailableUIViewController {
-    // convenience function for casting and to "mask" the recursive function
-    return (UIViewController *)[self traverseResponderChainForUIViewController];
-}
-
-- (id) traverseResponderChainForUIViewController {
-    id nextResponder = [self nextResponder];
-    if ([nextResponder isKindOfClass:[UIViewController class]]) {
-        return nextResponder;
-    } else if ([nextResponder isKindOfClass:[UIView class]]) {
-        return [nextResponder traverseResponderChainForUIViewController];
-    } else {
-        return nil;
-    }
-}
-
 #pragma mark - Lifecycle
 
 - (void)removeFromSuperview