Value: 16843309
Specify whether an activity should be kept in its history stack. If this attribute is set, then as soon as the user navigates away from the activity it will be finished and they will no longer be able to return to it.
Must be a boolean value, either "true" or "false".
This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.