Fix update sync status

SetProgressBarIndeterminateVisibility was not called on the UI thread. This is fixed by sending MainActivity.ReplicationChanged()'s operations to run on the UI thread.
Merge pull request #39 from couchbaselabs/fix-update-sync-status

Fix update sync status
Revert the fixed for sync status update

The issue has already been fixed in Replication.cs by ensuring that the callback will be run on the captured context which is the UI Thread.
Update Details.md
Merge branch 'master' of https://github.com/couchbaselabs/couchbase-lite-net