Bootanimation: Fix the low memory device oom when run boot animation

Low memory device is easily to be oom when run boot animation. Here
we do optimize the boot animation GL Texture only one frame needed.
That is free timely and re-init it again. When in boot animation,
the fps=15, so it is ok to do the delete and re-init.

CRs-Fixed: 572325
Change-Id: I1e81c3d0f3600ac895f9bd7bd00a284f3d4b7d4c