BLASTBufferQueue: Avoid unnecessary transactions

Currently every call to getOrCreateBLASTSurface produces a transaction.
This transaction has two parts, both of which can be eliminated:
	1. The first is the reparent. This was written when the
	client allocated the BLAST SurfaceControl, but now the WM
	allocates it and it has the correct parent to start, so
	we can just eliminate this.
	2. Showing the surface. We can eliminate this by just showing
	the surface by default.

Bug: 152501055
Test: Flip BLAST flag. Play.
Change-Id: If6e28e9153a09909fb3bb061980deb82c132dd5a