Refactor UnusedAppsFragment to support more Unused periods

Refactor Months enum to UnusedPeriod enum, in order to support 1 month unused period on TV.
Simplify logic of generating UnusedPackageCategoriesLiveData. Add support to UnusedAppsFragment for different UnusedPeriods.

Relnote: Improving user info message about Unused Apps Hibernation.

Bug: 251747762

Test: Locally on TV with m -j50 GooglePermissionController
Change-Id: I4165b840ec38b53a6bc5290fa778a0409a5986a3
(cherry picked from commit f0bcebff)
(cherry picked from commit bf6cb8e288da7debc46f9516367c023b14a265c9)
Merged-In: I4165b840ec38b53a6bc5290fa778a0409a5986a3