R1:e44b40ca4d83

Make "Subscribe/Unsubscribe" require only "CAN_VIEW", not "CAN_INTERACT"

Summary:
Ref T13249. See PHI1059. Currently, Subscribe/Unsubscribe require CAN_INTERACT via the web UI and no permissions (i.e., effectively CAN_VIEW) via the API.

Weaken the requirements from the web UI so that you do not need "CAN_INTERACT". This is a product change to the effect that it's okay to subscribe/unsubscribe from anything you can see, even hard-locked tasks. This generally seems reasonable.

Increase the requirements…