Android encoder framework reuses the same gpu buffers as
inputs and doesn't call lock/unlock explicitly between writes.
If there is format conversion, this is fine since we will
read back what we've written first and then put it in another
buffer. Whenever there is no format conversion, this causes
sync issue on ARCVM since host side buffers never get updated.
Fix this by explicitly calling lock/unlock before sending buffer
to encoder.

Bug: 268317650
Test: atest com.google.android.media.gts.RtcVideoCodecTest#testDynamicBitrateChangeVp8
Change-Id: Ia1750aa37c2d879ddff0301814e489974f218f5c