Fix bubble for video call upgrade and multiple voice call.

To make sure bubble is dismissed on video call connected but isn't dismissed on
non-last multiple voice call disconnected.

Receive upgrade, declined and accepted:
https://drive.google.com/a/google.com/file/d/0Bz1rQbdSCWSKMFc4aDRFdi1xYTQ
Request upgrade, declined and accepted:
https://drive.google.com/a/google.com/file/d/0Bz1rQbdSCWSKelZZSURwTjBiYnM
Multiple voice call:
https://drive.google.com/a/google.com/file/d/0Bz1rQbdSCWSKNEhNWGdzWFAtTlE

Test: manual
PiperOrigin-RevId: 162288587
Change-Id: Idfa8efa3eb96980ab17694b8fe4d31fa8eb3e18d
diff --git a/java/com/android/incallui/ReturnToCallController.java b/java/com/android/incallui/ReturnToCallController.java
index 57d50ad..978b140 100644
--- a/java/com/android/incallui/ReturnToCallController.java
+++ b/java/com/android/incallui/ReturnToCallController.java
@@ -134,11 +134,15 @@
 
   @Override
   public void onDisconnect(DialerCall call) {
-    if (bubble != null && bubble.isVisible() && !TelecomUtil.isInCall(context)) {
+    boolean hasAnotherCall = CallList.getInstance().getActiveOrBackgroundCall() != null;
+    if (bubble != null
+        && bubble.isVisible()
+        && (!TelecomUtil.isInCall(context) || hasAnotherCall)) {
       bubble.showText(context.getText(R.string.incall_call_ended));
     }
-
-    hide();
+    if (!hasAnotherCall) {
+      hide();
+    }
   }
 
   @Override