Refactored ViewModels to be in their own folder

Other form factors will need to use the ViewModels, so they shouldn't be
in the "handheld" ui folder. Also removed reliance on the handheld UI's
"createArgs" methods.

Test: Navigate around the permission controller UI, ensure screens still
work
Fixes: 150235513
Change-Id: I5a4804da72de283a10d345f584f86f3e0a0baadb