Admin Reskin: Fix mobile list table control heights.

On the mobile admin viewport, interactive elements on list table pages had inconsistent heights. Give them a consistent height.

Follow-up to [61645].

Props andrewssanya, sainathpoojary, wildworks.
See #64999.

git-svn-id: https://develop.svn.wordpress.org/trunk@62400 602fd350-edb4-49c9-b593-d223f7449a82