BLASTBufferQueue: Fix unnecessary copying of Surface

When we call mSurface.transferFrom(getOrCreateBLASTSurface()) we
always end up incrementing mSurface.generationId, because
BLASTBufferQueue.java::getSurface will always return a new native
wrapper object. We had a similar situation with
mSurface.copyFrom(mSurfaceControl), and had to build IGBP
comparison in to the native method. Here though, it's easier
to just rely on the stability of the Surface (never changes
for the lifetime of the BLASTBufferQueueAdapter) to avoid
duplicate calls to transferFrom.

Bug: 152501005
Test: Existing tests pass.
Change-Id: I64b9a6ae3cabfa75974e040460638417bfac6845