Prevent NetworkRequestDialogActivity recreation on some configuration change

NetworkRequestDialogActivity's internal state gets reset if
Configuration change happens, for example rotation or resize.
This change prevents such an unwanted restart of Activity.

Bug: 314893682
Test: resizing the dialog won't trigger restart.
Change-Id: Ia628db81b76d8b15f2ac11f53652e444c44f564d
(cherry picked from commit c53818a4569ce011820732d842eaa57ab1bcc52b)