Add functional test for update of group of provider resources

A new test which tests the (previously buggy) behavior when updating
a nested stack of more than one level of nesting, specifically updating
a ResourceGroup which contains provider resources.

Change-Id: I8abfd99f1ecc2cc84410fb552f18f93e47144c17
Related-Bug: #1389499
Merge "Add functional test for update of group of provider resources"