Settings: Fix sometimes reset progress dialog not dismissed

The display of reset progress dialog takes time. User can initiate multiple clicks and show multiple progress dialogs during the internal. But in fact, only once dismiss request initiated.

Check the reset progress dialog, if it is showing, dismiss it firstly before show another reset progress dialog.

Change-Id: Ia944990ea489927b38be59b1f7a8ad66fc8b669a
Buganizer: 227413950