Add a new constant to TimeZoneRulesDataContract

This enables time zone data app code (provided by Google)
to check the manifest (provided by the OEM) uses the right permission
without referencing internal manifest permission Strings directly.

Bug: 64139059
Test: Ran internal xTS tests
Change-Id: I4b1a8608beff3b5218ecf5162cfe8e31027e2007
(cherry picked from commit 8e2a8575)