Always re-register AlarmManager broadcast and send widget update when package is unstopped

Updates AppWidgetServiceImpl to always re-register AlarmManager
broadcast and send APPWIDGET_UPDATE when the package is unstopped, even
if we have not observed a change in masked state.

We may have received a PACKAGE_RESTARTED, but did not mask the widget
(masked == false) because the package was already unstopped by the time
we queried PackageManager.isPackageStoppedForUser. In that case, the
PendingIntents for this widget will have still been cancelled, and we
need to trigger a widget update so that the provider can create new
PendingIntents for their widget. Also, the broadcast has been cleared
from AlarmManager and must be re-registered.

Bug: 435687711
Test: force-close Google app and verify expected search widget behavior
Flag: EXEMPT bug fix
Change-Id: I928bb2e18c8d66bc984593f367f4416228cf3e90