Telephony mainline updates.

- Remove uses of TelecomManager#from and replace with proper
Context#getSystemService invocations.
- In NotificationManager#getShowVoicemailIntentForDefaultDialer, use a new
Telecom system API to get the dialer for a specific user instead of using
DefaultDialerManager directly.
- Update references to ConferenceParticipant which is not internal to
IMS.
- Remove Telecom logging references.

Bug: 141576016
Test: Manual smoke test.
Test: Run unit tests.
Test: Run CTS tests.
Change-Id: If1090036d349cc72f86d523b781e09cd37cf0871
Merged-In: If1090036d349cc72f86d523b781e09cd37cf0871
23 files changed