Delete VectorDrawableAtlas

Poking around in a few apps it doesn't appear that
the VectorDrawableAtlas is achieving sufficient
utilization to justify its existence. The potential for
draw call merging doesn't seem warranted for the
RAM cost of the atlas.

Bug: 137853925
Test: builds
Change-Id: Id2419bc6dccb6316636d50c568f8fac75a2d563f