Fixes back button on action bar on some fragments.

SettingsPreferenceFragment has this already set so that the drawer
layout will work when the menu doesn't exist. However, some fragments
are not preference fragments, and we need to set setHasOptionsMenu
manually.

bug:27879503
Change-Id: I6faadeb56dab00af611ac413109800822038c66d

src/com/android/settings/ResetNetwork.java

@@ -50,7 +50,7 @@ import static com.android.settingslib.RestrictedLockUtils.EnforcedAdmin;
  *
  * This is the initial screen.
  */
-public class ResetNetwork extends InstrumentedFragment {
+public class ResetNetwork extends OptionsMenuFragment {
     private static final String TAG = "ResetNetwork";
 
     // Arbitrary to avoid conficts