OAK-1462 - Aggregate Index isn't usable in an osgi environment

Updating test to check the aggregation logic. Thanks Alex for the guidance!

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1602120 13f79535-47bb-0310-9956-ffa450edef68
OAK-1462 - Aggregate Index isn't usable in an osgi environment

Updating to pick RepositoryInitializer from the service registry. This is required by tests to provide extra initial content

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1602121 13f79535-47bb-0310-9956-ffa450edef68