Android: Resize the video correctly on layout changes (#432)

The transform matrix was not being recalculated when the View
dimensions changed. Fixed by copying the code from the scaleVideoSize
method from the ScalableVideoView.

https://github.com/yqritc/Android-ScalableVideoView/blob/master/library/src/main/java/com/yqritc/scalablevideoview/ScalableVideoView.java#L95