Expose selector draw condition for test

There is no other way for a test to inspect whether the
selector drawable will be drawn or not. This adds a hidden
test api to expose it

Bug: 67881712
Test: AbsListViewTest#testSelectorOnScreen
Change-Id: I3b6d25a0c8cb0c5f6c8bfc45eaa2660caa133b7d
2 files changed