Camera2 API: enable burst capture and repeating burst.

*  Enable sending out burst requests, canceling, and flushing.
*  Enable onCaptureStarted, onResultReceived for bursts.
*  Enable onCaptureSequenceCompleted by tracking frame number.

Change-Id: Ica2b031cac7ad90f9c4b74a78e6185e627195340
Bug-ID: 10749500