Add GPU completion to FrameMetrics (1/3)

- Add SurfaceStatsCallback to TransactionCompletedListener
- Register a callback in RenderProxy to be called when we have
surface stats from SF via the BLAST callback.
- Instead of finishing a frame for frame metrics reporting
immediately, wait until BLAST callback fires, note GPU completion
time and finish frame.
- Expose GPU_COMPLETION in FrameMetrics
- Modify TOTAL_DURATION to also include GPU_COMPLETION

Test: FrameMetricsListenerTest
Fixes: 171046219
Change-Id: I16fa1d80cfc4e7a5527c18fec7e885409f17ee4d