修复playButton可能被挡住的问题

TZImagePickerController/TZImagePickerController/TZPhotoPreviewCell.m

@@ -418,6 +418,7 @@
     [_playButton setImage:[UIImage tz_imageNamedFromMyBundle:@"MMVideoPreviewPlay"] forState:UIControlStateNormal];
     [_playButton setImage:[UIImage tz_imageNamedFromMyBundle:@"MMVideoPreviewPlayHL"] forState:UIControlStateHighlighted];
     [_playButton addTarget:self action:@selector(playButtonClick) forControlEvents:UIControlEventTouchUpInside];
+    _playButton.frame = CGRectMake(0, 64, self.tz_width, self.tz_height - 64 - 44);
     [self.contentView addSubview:_playButton];
     [self.contentView addSubview:_iCloudErrorIcon];
     [self.contentView addSubview:_iCloudErrorLabel];
@@ -475,7 +476,7 @@
     self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
     self.playerLayer.backgroundColor = [UIColor blackColor].CGColor;
     self.playerLayer.frame = self.bounds;
-    [self.layer addSublayer:self.playerLayer];
+    [self.contentView.layer addSublayer:self.playerLayer];
     [self configPlayButton];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(pausePlayerAndShowNaviBar) name:AVPlayerItemDidPlayToEndTimeNotification object:self.player.currentItem];
 }