Add TimeZoneRulesDataContract to system API

Add TimeZoneRulesDataContract to system API and remove
TODOs to add other classes that should not now be needed
in the system API (since they are used by a platform-only
app).

Bug: 31008728
Test: make droid
Change-Id: I600e7b08853b86b27463193411cf85207ae09ce8
2 files changed