Reuse the back button confirmation dialog for the close button. The
condition is slightly different: need confirmation if there are any
manually-entered values for any parameter AND the user has edited
the template in this session.
The "reset" action was synthetic, only used internally and not
connected to buttons or menus. Canonically, action='' is the close
action for OOUI.
Bug: T297792
Change-Id: I4ff644c7ab24ed9ba1a4c27d762563c5d6771cfc
Currently, the insert template dialog includes a back button in the
upper corner. Confirmation of abandoning unsaved changes was
accomplished in an overlay panel. This patch rewrites as a dialog
and updates the on-screen text.
Bug: T297792
Change-Id: Ifa2ff97c9284609ee2a784f455789c56a762ba50