Fixed accessibility issues in Wi-Fi password view in Settings

- Keep the Save button enabled at all times

- Show "*required" or "The password is invalid" to remind the user
  - Show "Password (optional)" to indicate that it can remain unchanged, when modifying Wi-Fi configuration

Bug: 386897596
Bug: 402694144
Flag: EXEMPT bugfix
Test: Manual testing
  atest SettingsUnitTests:AddNetworkFragmentTest
  atest WifiConfigControllerTest \
        WifiConfigController2Test \
        WifiDialogActivityTest
Change-Id: I09b7684674ff376139565fcc196cde8d8d20a864

src/com/android/settings/wifi/WifiDialog.java

@@ -118,7 +118,7 @@ public class WifiDialog extends AlertDialog implements WifiConfigUiBase,
             mController.hideForgetButton();
         }
 
-        mDialogHelper = new WifiDialogHelper(this, mController.getValidator());
+        mDialogHelper = new WifiDialogHelper(this, this, mController.getValidator());
     }
 
     @SuppressWarnings("MissingSuperCall") // TODO: Fix me
@@ -159,6 +159,9 @@ public class WifiDialog extends AlertDialog implements WifiConfigUiBase,
     public void onClick(DialogInterface dialogInterface, int id) {
         if (mListener != null) {
             switch (id) {
+                case BUTTON_SUBMIT:
+                    mListener.onSubmit(this);
+                    break;
                 case BUTTON_FORGET:
                     if (WifiUtils.isNetworkLockedDown(getContext(), mAccessPoint.getConfig())) {
                         RestrictedLockUtils.sendShowAdminSupportDetailsIntent(getContext(),
@@ -171,11 +174,6 @@ public class WifiDialog extends AlertDialog implements WifiConfigUiBase,
         }
     }
 
-    /** Return true to tell the parent activity to call onSubmit before onDismiss. */
-    public boolean shouldSubmitBeforeFinish() {
-        return mDialogHelper.isPositive();
-    }
-
     @Override
     public int getMode() {
         return mMode;