Fix flashlight availability.

Bug: 26981482
Change-Id: I62059b3b7f18520ae8735f3f3557411991bee909

packages/SystemUI/src/com/android/systemui/qs/tiles/FlashlightTile.java

@@ -68,6 +68,11 @@ public class FlashlightTile extends QSTile<QSTile.BooleanState> implements
         return new Intent(MediaStore.INTENT_ACTION_STILL_IMAGE_CAMERA);
     }
 
+    @Override
+    public boolean isAvailable() {
+        return mFlashlightController.hasFlashlight();
+    }
+
     @Override
     protected void handleClick() {
         if (ActivityManager.isUserAMonkey()) {

packages/SystemUI/src/com/android/systemui/statusbar/policy/FlashlightController.java

@@ -93,6 +93,10 @@ public class FlashlightController {
         }
     }
 
+    public boolean hasFlashlight() {
+        return mCameraId != null;
+    }
+
     public synchronized boolean isEnabled() {
         return mFlashlightEnabled;
     }