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
diff --git a/src/com/android/phone/CallFeaturesSetting.java b/src/com/android/phone/CallFeaturesSetting.java
index 17a1734..3858595 100644
--- a/src/com/android/phone/CallFeaturesSetting.java
+++ b/src/com/android/phone/CallFeaturesSetting.java
@@ -214,7 +214,7 @@
         mSubscriptionInfoHelper.setActionBarTitle(
                 getActionBar(), getResources(), R.string.call_settings_with_label);
         mPhone = mSubscriptionInfoHelper.getPhone();
-        mTelecomManager = TelecomManager.from(this);
+        mTelecomManager = getSystemService(TelecomManager.class);
     }
 
     private void updateImsManager(Phone phone) {