Prevent deadlock for clearWaitingDialog

Post the dismiss work to prevent the deadlock between the global lock
and the ActivityManagerService.

Bug: 230077383
Test: atest CtsWindowManagerDeviceTestCases
Change-Id: Ie4bbec94d2ac9bd3aaa4f1af8c009c5d81f3ab00

services/core/java/com/android/server/am/ErrorDialogController.java

@@ -144,7 +144,8 @@ final class ErrorDialogController {
         if (mWaitDialog == null) {
             return;
         }
-        mWaitDialog.dismiss();
+        final BaseErrorDialog dialog = mWaitDialog;
+        mService.mUiHandler.post(dialog::dismiss);
         mWaitDialog = null;
     }