Restrict activity launch when caller is running in the background

Test: test on device + atest-src BackgroundActivityLaunchTest#testBackgroundActivityBlockedInStartNextMatchingActivity
Bug: 230492947
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:3e9da3ec4705b072dbe8a10e8ffc841f4928381c)
Merged-In: Ie774b142a7fab12d596ccd64872b781e3825e9ba
Change-Id: Ie774b142a7fab12d596ccd64872b781e3825e9ba