Ignore virtual presentation windows

Windows of TYPE_PRESENTATION on virtual displays should not be counted
as visible windows to determine if BAL is allowed.

Test: manual test, atest BackgroundActivityLaunchTest
Bug: 264029851, 205130886
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:050005fd2f19a5bc2d7a1c7786b4ded1945fb807)
Merged-In: I08b16ba1c155e951286ddc22019180cbd6334dfa
Change-Id: I08b16ba1c155e951286ddc22019180cbd6334dfa