Remove the extra buffer allocation from hwui

SurfaceFlinger will set the maxAcquiredBufferCount on the buffer queue
to account for the extra buffers needed, depends on the refresh rate
and app/sf durations, and there is no needed for any addional buffer
allocation is hwui.

Test: TBD
Bug: 188553729
Change-Id: Ic441a6feb15f6b084d45c9e538b11b7b24e36a0e