Add group Ids to facilitate Merged PhoneAccounts

Adds a Group Id to Merged PhoneAccounts that are registered to
Telecom. If a SIM with a merged IMSI is the user selected default, we
will now not lose the default calling account settings when the underlying
PhoneAccount changes transparently to the user.

Bug: 28173788
Change-Id: I0410bc6c08ad9edbfc80f921e3f62e95373a69e0
1 file changed