Only re-register callbacks if tuning changed

We only need to get the state if the tuning has actually changed.
Currently we hit this every time we open QS which breaks the alpha
animation on the mobile icon.

Bug: 21791609
Change-Id: I3d77a2d0f81d2d7bed600ccd7a2d2c2b4a262db7
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java b/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java
index ff7b37f..9e0b08b 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java
@@ -114,14 +114,21 @@
             return;
         }
         ArraySet<String> blockList = StatusBarIconController.getIconBlacklist(newValue);
-        mBlockAirplane = blockList.contains(SLOT_AIRPLANE);
-        mBlockMobile = blockList.contains(SLOT_MOBILE);
-        mBlockWifi = blockList.contains(SLOT_WIFI);
-        mBlockEthernet = blockList.contains(SLOT_ETHERNET);
+        boolean blockAirplane = blockList.contains(SLOT_AIRPLANE);
+        boolean blockMobile = blockList.contains(SLOT_MOBILE);
+        boolean blockWifi = blockList.contains(SLOT_WIFI);
+        boolean blockEthernet = blockList.contains(SLOT_ETHERNET);
 
-        // Re-register to get new callbacks.
-        mNC.removeSignalCallback(SignalClusterView.this);
-        mNC.addSignalCallback(SignalClusterView.this);
+        if (blockAirplane != mBlockAirplane || blockMobile != mBlockMobile
+                || blockEthernet != mBlockEthernet || blockWifi != mBlockWifi) {
+            mBlockAirplane = blockAirplane;
+            mBlockMobile = blockMobile;
+            mBlockEthernet = blockEthernet;
+            mBlockWifi = blockWifi;
+            // Re-register to get new callbacks.
+            mNC.removeSignalCallback(this);
+            mNC.addSignalCallback(this);
+        }
     }
 
     public void setNetworkController(NetworkControllerImpl nc) {