Depends on D18924. Ref T13048. Each adapter defines which repetition options ("every time", "only the first time") users may select for rules.
Currently, this is all explicit and hard-coded. However, every adapter really just implements this rule (except for some bugs, see below):
You can pick "only the first time" if this adapter fires more than once on the same object.
Since we already have a isSingleEventAdapter() method which lets us tell if an adapter fires more than once, just write this rule in the base class and delete all the copy/pasting.
This also fixes two bugs because of the copy/pasting: Pholio Mocks and Phriction Documents did not allow you to write "only the first time" rules. There's no reason for this, they just didn't copy/paste enough methods when they were implemented.
This will make a future diff (which introduces an "if the rule did not match last time" policy) cleaner.