Fixed it by adding a new media query for <720px and defining `default` for MobileOptions regardless of screen width.
Bug: T202557
Change-Id: I11deac1a36d9ab02ccfbce639490a95ca176f136
T140804 dropped the support for deviceTabletWidth in core
(https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/451648/9/includes/DefaultSettings.php)
This causes errors in these skinStyle files which are presumably not
being checked with CI.
Update these usages to use width-breakpoint-tablet instead
Bug: T202021
Change-Id: Ie804f24275c99c939687d59cca9d62204fd74518
Use local imports instead given all relevant files are within the
same repository, and don't vary by configuraion.
Bug: T140807
Depends-On: If3edac9a35b346af0320c12f70c0d978a6346201
Change-Id: Ife3cc345a63aff452e93accbe0a593fbaa358732
