Fix monkey crash

Bug: 8011964
Change-Id: Idafdb7b3bc22d3280e0aa93877b7e09a23270149
diff --git a/src/com/android/settings/wifi/WifiSettings.java b/src/com/android/settings/wifi/WifiSettings.java
index 4b2a0c9..cf27dd5 100644
--- a/src/com/android/settings/wifi/WifiSettings.java
+++ b/src/com/android/settings/wifi/WifiSettings.java
@@ -953,7 +953,9 @@
         if (button == WifiDialog.BUTTON_FORGET && mSelectedAccessPoint != null) {
             forget();
         } else if (button == WifiDialog.BUTTON_SUBMIT) {
-            submit(mDialog.getController());
+            if (mDialog != null) {
+                submit(mDialog.getController());
+            }
         }
     }