Reduce the latecy of encoding 1st frame

Current encode batching mandates delay for the first frame. Since photo
images are one frame, reduce the latency for encoding the first frame

Test: atest android.media.cts.VideoEncoderTest
Bug: 145356198
Change-Id: I6a8f7dd374a3252ba93f386d3c62cd735fe82802
(cherry picked from commit 84e512b6)
Merged-In: I6a8f7dd374a3252ba93f386d3c62cd735fe82802