Media: Refresh the window-wide uploader whenever a state is activated....

Media: Refresh the window-wide uploader whenever a state is activated. Properly unbind controller events. fixes #22504, see #21390.


git-svn-id: https://core.svn.wordpress.org/trunk@22791 1a063a9b-81f0-0310-95a4-ce76da25c4cd