Show on hold in management screen for conference call.

Do the following when a participant is on hold:
- Add "On hold • " in front of the number
- Gray out avatar and text (contact name & number)

Notice:
We only have the on hold state information for VoLTE conference call and IMS conference call. So the change only works for them (not for GSM/CDMA conference call).
Test: ConferenceManagerPresenterTest
PiperOrigin-RevId: 171345423
Change-Id: Ie5fe2fc1097f4858604283989dcb916c2ac21972
diff --git a/java/com/android/incallui/call/DialerCall.java b/java/com/android/incallui/call/DialerCall.java
index 82a29ee..d393b42 100644
--- a/java/com/android/incallui/call/DialerCall.java
+++ b/java/com/android/incallui/call/DialerCall.java
@@ -706,6 +706,10 @@
     }
   }
 
+  public int getNonConferenceState() {
+    return mState;
+  }
+
   public void setState(int state) {
     if (state == State.INCOMING) {
       mLogState.isIncoming = true;