BG-FGS-launch restriction exemptions.

1. Add a new permission START_FOREGROUND_SERVICES_FROM_BACKGROUND.
2. Add a new bind flag BIND_ALLOW_FOREGROUND_SERVICE_STARTS_FROM_BACKGROUND
3. BroadcastOptions.setTemporaryAppWhitelistDuration() is currently
protected with CHANGE_DEVICE_IDLE_TEMP_WHITELIST permission, also open
it for START_ACTIVITIES_FROM_BACKGROUND and
START_FOREGROUND_SERVICES_FROM_BACKGROUND permission.
4. Exempt SYSTEM_ALERT_WINDOW permission.
5. if Context.startForegroundService() or Service.startForeground() is
restricted by BG-FGS-launch restriction, and app's targetSdkVersion is S
and above, throw a IllegalStateException.

Bug: 171305836
Test: atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java#testFgsBindingFlagFGS
atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java#testFgsBindingFlagActivity
atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java#testFgsStartSystemAlertWindow
atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java#testFgsStartFromBGException

Change-Id: Iff3ed65e174a8406d4d6045cda42bdde6cecf30d