Define a set of methods on Launcher which can be safely called externally

-> The methods are defined by an interface, LauncherExterns, which Launcher
   implements

Change-Id: I61362761f5d90fbc3011ce000944768d5ab29d43
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 4e379a1..51df013 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -136,8 +136,8 @@
  * Default launcher application.
  */
 public class Launcher extends Activity
-        implements View.OnClickListener, OnLongClickListener, LauncherModel.Callbacks,
-                   View.OnTouchListener, LauncherProviderChangeListener,
+        implements LauncherExterns, View.OnClickListener, OnLongClickListener,
+                   LauncherModel.Callbacks, View.OnTouchListener, LauncherProviderChangeListener,
                    AccessibilityManager.AccessibilityStateChangeListener {
     public static final String TAG = "Launcher";
     static final boolean LOGD = false;
@@ -1842,7 +1842,7 @@
         return mModel;
     }
 
-    protected SharedPreferences getSharedPrefs() {
+    public SharedPreferences getSharedPrefs() {
         return mSharedPrefs;
     }