libui: update for revised HIDL gralloc

The revised HIDL gralloc is implementable on top of gralloc0 and
gralloc1, which enables us to remove all legacy code.

However, it lacks the ability to query buffer properties from a
buffer handle.  GetBufferFromHandle in VR always fails.

Bug: 36481301
Test: builds and boots on Pixel
Change-Id: Id7cfa2d2172dfc008803860f24fcf4f03ba05f11