Contract Upgrade flows basically unusable with anonymous identities

[adamschoenemann]

corda/core/src/main/kotlin/net/corda/core/flows/AbstractStateReplacementFlow.kt

Lines 183 to 184 in 241170f

	// TODO: use keys from the keyManagementService instead
	// TODO Check the set of multiple identities?

If you use an anonymous identity to sign your states (as is recommended), then contract upgrade flows will not work because of the referenced todos.
Basically, it will always say that you're not referenced in any input states and then quit.
Seems to me the fix is is just a few lines of kotlin...

[r3jirabot]

Automatically created Jira issue: CORDA-4164

[adamschoenemann]

Proposed change to fix: #6959

[nargas-ritu]

Logged in the backlog for an internal review.