Clarify REMOTE disconnect cause API docs.

Update API docs for REMOTE to make it clear that this disconnect cause is
used both for user-initiated disconnection on behalf of the remote party,
and for cases where the remote party never answered the call.

Test: Docs only change
Fixes: 280505750
Change-Id: Id718c75e2b748d2b5d5778f89d3dd7a420845418

telecomm/java/android/telecom/DisconnectCause.java

@@ -43,8 +43,8 @@ public final class DisconnectCause implements Parcelable {
     /** Disconnected because of a local user-initiated action, such as hanging up. */
     public static final int LOCAL = TelecomProtoEnums.LOCAL; // = 2
     /**
-     * Disconnected because of a remote user-initiated action, such as the other party hanging up
-     * up.
+     * Disconnected because the remote party hung up an ongoing call, or because an outgoing call
+     * was not answered by the remote party.
      */
     public static final int REMOTE = TelecomProtoEnums.REMOTE; // = 3
     /** Disconnected because it has been canceled. */