Close the Drawer on BACK button if the Drawer is opened

- otherwise (if Drawer is closed), BACK should work as BACK
into the Fragments BackStack

Change-Id: Ic7f500eb77f35e2142a40e6c9e34c4e7f0ec6428

src/com/android/settings/SettingsActivity.java

@@ -702,6 +702,15 @@ public class SettingsActivity extends Activity
         return mFirstHeader;
     }
 
+    @Override
+    public void onBackPressed() {
+        if (mDrawerLayout.isDrawerOpen(mDrawer)) {
+            mDrawerLayout.closeDrawer(mDrawer);
+            return;
+        }
+        super.onBackPressed();
+    }
+
     @Override
     public void onBackStackChanged() {
         setTitleFromBackStack();