Fix active call InCallUI buttons highlight when EM call disconnects

Update active call buttons color in updateButtonsState
to update button background color when foreground
emergency call disconnects with different background
color for buttons.

Change-Id: I5d7e5aeff1482d1df663718c02a2bf1f0203c5bf
CRs-Fixed: 1065725
diff --git a/InCallUI/src/com/android/incallui/CallButtonPresenter.java b/InCallUI/src/com/android/incallui/CallButtonPresenter.java
index ea9273f..ceae8c0 100644
--- a/InCallUI/src/com/android/incallui/CallButtonPresenter.java
+++ b/InCallUI/src/com/android/incallui/CallButtonPresenter.java
@@ -572,6 +572,7 @@
         }
 
         ui.updateButtonStates();
+        ui.updateColors();
     }
 
     private boolean hasVideoCallCapabilities(Call call) {