Verifies that policy changes trigger rule updates that respect current
foregroundActivities status. Also verifies logic that promotes a UID
based on its most-foreground PID. Verifies that policy changes result
in immediate rule changes.
Also verifies that BACKGROUND_DATA_SETTING_CHANGED broadcasts are sent
by policy changes.
Change-Id: I4fd0dad9e1dbccee2c5968244bb1814e6cb2c6e1