Add permission to the list of individually toggleable modules

This is safe even though permission is not an optional mainline
module because devices that support mainline must pass GTS and
testModulesSignedCorrectly and testModulesPreloadedCorrectly in GTS
currently tests this, along with testMainlineApprovedTrain which checks
mandatory/optional, signing keys, and if what's preloaded are part of
approved trains.

Bug: 238175656
Test: # Cherry pick to branch that has Google signed prebuilts for
      # permission and builds from prebuilts by default.
      # Update the permission to an sdk snapshot generated with
      # r.android.com/2151273.
      # Make sure that the permission is built from prebuilts by
      # default
Change-Id: Id4eb9ba0da8a05c41d3b29b1cb8fa1d2d485c7b9