Fix the settings crash when SimDialogActivity is null

The PreferredSimDialogFragment did updateDialog after SimDialogActivity
was finished. It caused the settings crash. This is similar to b/184899699

Bug: 220803944
Test: build pass
Change-Id: I9a5964400a63053e362632944b9e7aa8ec1bbea8

src/com/android/settings/sim/PreferredSimDialogFragment.java

@@ -84,10 +84,11 @@ public class PreferredSimDialogFragment extends SimDialogFragment implements
     private void updateDialog(AlertDialog dialog) {
         Log.d(TAG, "Dialog updated, dismiss status: " + mWasDismissed);
 
-        final SubscriptionInfo info = getPreferredSubscription();
         if (mWasDismissed) {
             return;
         }
+
+        final SubscriptionInfo info = getPreferredSubscription();
         if (info == null) {
             dismiss();
             return;

src/com/android/settings/sim/SimDialogFragment.java

@@ -83,6 +83,12 @@ public abstract class SimDialogFragment extends InstrumentedDialogFragment imple
         }
     }
 
+    @Override
+    public void dismiss() {
+        mChangeListener.stop();
+        super.dismiss();
+    }
+
     public abstract void updateDialog();
 
     @Override

src/com/android/settings/sim/SimListDialogFragment.java

@@ -128,12 +128,13 @@ public class SimListDialogFragment extends SimDialogFragment {
     @Override
     public void updateDialog() {
         Log.d(TAG, "Dialog updated, dismiss status: " + mWasDismissed);
+        if (mWasDismissed) {
+            return;
+        }
 
         List<SubscriptionInfo> currentSubscriptions = getCurrentSubscriptions();
         if (currentSubscriptions == null) {
-            if (!mWasDismissed) {
-                dismiss();
-            }
+            dismiss();
             return;
         }
         boolean includeAskEveryTime = getArguments().getBoolean(KEY_INCLUDE_ASK_EVERY_TIME);