[Android] Tests for multiple item collection changes in CollectionView (#4869)

[Android] Tests for multiple item collection changes in CollectionView (#4869)

* Add multi-item removal test; handle multi-item removal scenarios on Android;

* Add test harness for adding multiple items to CollectionView at once

* Add test harness for multi-item move/replace; handle Android multi-item move;
Fix bug when replacing differently-sized item sets on Android;

* Add test harness for INotifyCollectionChanged Reset

* Performance improvements and clearer test code

* Remove private modifier

* Fix bug where updating items sources changed source types

* Remove private modifier

* Make index checks clearer

* Remove private modifier

* Remove private modifier

* Move code into if clause

* Use local variable

* Better indication of how to use collection modification tests

* Include end index in items moved

* Make update range include items between source and destination indexes

* Remove commented code