tweak button order for alien warn dialog

Change-Id: I6e51951df3bff0d1829bff8e2a436e4030247baf
(cherry picked from commit 2e8a1e1121bc23d442bf7be27e2ae6c15d101980)
swap button order in ui to match typical reality

This has no effect on the rendering of this .ui as native button ordering is
active. But it means that under the typical editing-under-GNOME that ones head
is wrecked from the cognitive impedance of the editor and viewer not matching
in order

Change-Id: I8888d4263f05bcecff72496f4cf0ae67345dc644
(cherry picked from commit bce7c9b0688c6f6f73311cc87ac094831489eedb)