allow phone error messages from lock screen

A partner reported that error messages did NOT pop up from a call
answered from the lock screen.  Upon inspection, they pointed out
that in PhoneDisplayMessage, the AlertDialog was not being passed
a flag that allowed lock screen pop up behavior.

see patchset 2 for manual test

bug: 234701394
Test: manual (issue a new shell cmd to generate a test error while
              in phone call that was answered from the lock screen)
Change-Id: I82f92cabd0d0d2e44548972a5bc25548729a6a7b
1 file changed