Use a broadcast receiver instead of a settings observer.

Settings observer doesn't work if a setting is modified in another
process, hence we instead register a receiver which listens for a signal
from the settings process that the rotation preference has changed.

Change-Id: I570e3c67bb64a32347e84ca00a8ac31d9010eac3
diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index cffcd34..b267f75 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -93,6 +93,9 @@
     private static boolean sForceEnableRotation = isPropertyEnabled(FORCE_ENABLE_ROTATION_PROPERTY);
 
     public static final String ALLOW_ROTATION_PREFERENCE_KEY = "pref_allowRotation";
+    public static final String SCREEN_ROTATION_SETTING_INTENT =
+            "come.android.launcher3.SCREEN_ORIENTATION_PREF_CHANGED";
+    public static final String SCREEN_ROTATION_SETTING_EXTRA = "screenRotationPref";
 
     public static boolean isPropertyEnabled(String propertyName) {
         return Log.isLoggable(propertyName, Log.VERBOSE);