Implement IcuZoneRulesProvider.

Implement IcuZoneRulesProvider to provide ZoneRules for java.time using
the data/API of ICU4J.

Modified artrun-testng to optionally take the name of the testng.xml
file and provide testng-time.xml file that lists all upstream tests we
imported. Also update artrun to correct list of boot dexjars.

Change ZoneRulesProvider.java to a non-JavaDoc file to avoid exposing it
as public API. Remove mention of ZoneRulesProvider from ZoneRules
JavaDoc. Removed TzdbZoneRulesProvider, which is not used on Android.

Bug: 28832222
Test: ran java.time testng changes (artrun-testng testng-time.xml) and
    IcuZoneRulesProviderTest

Change-Id: Ic24454f443ac8000fc50c2c2bddd6f28fc25bc0e