improvements of CBR on compainion devices

improve cbr on companion devices by display notification only when there is an active
bluetooth connections. If devices target on S+, it requires a new
runtime permission bluetooth_connect, grant those runtime permission for
default emergency alert module.

Bug: 181773113
Test: Manual test
Change-Id: Ie4d70e1d23e20015f6085db05ca8523b1f3c2ad4