Add a generic blue background on some homepage tiles

If a homepage tile is injected from external packages, we can't
control what their icons look like, so we put a generic blue circular
background to make it consistent with the other icons.

Change-Id: I2a935db37fff097ae15540262bff94efea55179a
Fixes: 69314641
Test: robotests

src/com/android/settings/dashboard/DashboardFeatureProvider.java

@@ -56,7 +56,9 @@ public interface DashboardFeatureProvider {
 
     /**
      * Whether or not we should tint icons in setting pages.
+     * @deprecated in favor of color icons in homepage
      */
+    @Deprecated
     boolean shouldTintIcon();
 
     /**