Fix android.app.cts.DisplayTest.

There are 2 issues in this test:
1) Deprecated methods Display#get{Width,Height} only refreshes its cache
after 20 ms, and it's possible the framework finishes work too fast and
Display simply returns the old cached value -- use new API that doesn't
have the limitation instead;
2) On docked devices the app is supposed to be letterboxed -- so only
one dimension is updated, not both.

Bug: 79984258
Test: Passed on docked device and walleye.
Change-Id: Ie344f5537c908b6b2e0fce946de6b241ce4d25d0
1 file changed