Adding new method required in Gingerbread.

MyTracksTest/src/com/google/android/apps/mytracks/io/backup/PreferenceBackupHelperTest.java

@@ -51,6 +51,11 @@ public class PreferenceBackupHelperTest extends TestCase {
       return true;
     }
 
+    @Override
+    public void apply() {
+      commit();
+    }
+
     @Override
     public Editor putBoolean(String key, boolean value) {
       return put(key, value);