Brightcove Native SDK for Android v10.4.5

OfflinePlayback Plugin Changes:
* Fixes offline captions only displaying in English regardless of user selection
* Fixes captions not displaying when playing downloaded video offline without prior online playback
* Filters caption selection dialog to only show captions that were actually downloaded
Exoplayer Changes:
* Fixes caption track selection for offline/local sources to properly route through ExoPlayer's native track selector
* Fixes caption stacking issue in BrightcoveClosedCaptioningView