[Doc'd] View compaction is triggered during rebalance when auto-compaction is disabled

Steps:
1. Set fragmentation threshold to 100% (both data and index)
2. Start workload, view fragmentation is high, >90%.
3. Rebalance cluster

As result view compaction kicks in. Bucket compaction doesn't kick in.

Not sure if it's a bug but behavior is very confusing. At least I didn't find documentation that explains it.

Diags for 2.0.2, just in case:
http://172.23.96.10:8080/view/views/job/apollo-views/116/artifact/

Basically I just want to run a test with no view compaction.