I have my current android application which do not allow user to take screen shot.
I am using getWindow().setFlags(LayoutParams.
Instead of prompting the 3rd party app, consider using a MapActivity.
Then you can you can place a MapView in the layout and show the Map. In this case, you will be able to control the restriction via the secure flag.
Just place the same code in the onCreate() method like you did on the other activity.