* Move auto-adjustments for transformation matrices from the
VideoTranscodingSamplePipeline constructor to the new
ScaleToFitFrameProcessor.
* Add GlFrameProcessor#getOutputDimensions() to allow for GlFrameProcessors with
different input and output dimensions. This is a prerequisite for
Presentation.
* Tested with unit tests (and manually just in case).
* A follow up CL will implement change the FrameProcessor input to be scale and
rotate values as requested by the user. This was kept out of this CL to
reduce CL review size. Presentation will also be implemented in a follow up
CL.
PiperOrigin-RevId: 434774854
371c5c1b2e