Make LUT metric test more reliable

* Explicitly push frames without LUTs, so that we don't have to rely on
  the UI layer reporting drawn frames with a LUT
* Run everything on the main thread since we don't care about
  performance, but would care about making sure there's no race conditions
* Add extra logging

Bug: 427448835
Flag: TEST_ONLY
Test: GraphicsAtomTests
Change-Id: If16ba85903012cff029a9cba85b131b39ff30423
1 file changed