support notification channel for non owner users

Telephony only runs under perimary users, we wont create a separate
stack for managed users or other secondary users but we still want to
show notifications if for other users to avoid missing any important
event. Today we loop through all users and call notifyAsUser for all
non-managed users one by one. But this has the issue has we dont have
separate notification channels for each user. The solution is call
notifyAsUser with UserHandle.ALL. this methods guarantees 1.no
notification mismatch for different users 2. single notification for all
users.

Bug: 64875812
Test: Manual test on managed user account/guest account and owner
account

Change-Id: I4a24d2c229614c46d4eb324742e18f6bbbbd6a80
1 file changed