Tidy up visuals/behaviors for MSIM notifications.

+ If MSIM device, show subscription display name on voicemail
or call forwarding notifications instead of some of the normal
title/summary text.
+ Use subscription colors to tint notification backgrounds.
+ Use PhoneAccountHandle to specify SIM to call with for voicemail
notifications.
+ Move code for getting PhoneAccountHandle from Phone into PhoneUtils
and update references throughout telephony. This assumes we only need
to do the conversion for PSTN phones; this seems to be a safe
assumption given how the notification manager previously got the
default Phone from the phone factory.

Bug: 18232725
Change-Id: I62574643de1d61ef716e06fb733467ce2f607586
5 files changed