Fix BackgroundActivityLaunchTest for TV

testBackgroundActivityNotBlockedWithinGracePeriod assumes that
the activity behind the test activity is the homescreen. This CL
replaces waitForHomeScreenVisible with waitAndAssertActivityRemoved
to remove this assumption. The semantics of the test stay the same

Bug: 189719530
Test: atest BackgroundActivityLaunchTest#testBackgroundActivityNotBlockedWithinGracePeriod
Change-Id: I6a242e6bf040d1fbbbdc643eb1f5cd074f17b924
1 file changed