Use androidx version of AlertDialog
Summary:
Use androidx version of AlertDialog to get properly styled AlertDialog buttons
Use PreferenceManager context to style Device Name AlertDialog
Test Plan: Apply patch and verify that AlertDialogs have properly styled buttons
Reviewers: KDE Connect, albertvaka
Reviewed By: KDE Connect, albertvaka
Subscribers: albertvaka, kdeconnect
Tags: KDE Connect
Differential Revision: https://phabricator.kde.org/D18298