## Bug description

When filtering insights by active feature flags, and trying to select a single feature flag (by using a `contains` selector), events are not being correctly filter (i.e. no events are returned). This presumably happens because the `active_feature_flags` attribute is stored as an array and the operator does not work properly on CH.

## Expected behavior

Relevant events should be loaded.

## How to reproduce

1. Create an insights graph, filter by "Active feature flags" using a contain selector.

Alternatively, just open [this graph](https://app.posthog.com/insights?actions=%5B%7B%22id%22%3A1578%2C%22name%22%3A%22created%20action%22%2C%22type%22%3A%22actions%22%2C%22order%22%3A0%7D%5D&events=%5B%5D&new_entity=%5B%5D&interval=week&date_from=-90d&breakdown=false&breakdown_type&properties=%5B%7B%22key%22%3A%22%24active_feature_flags%22%2C%22value%22%3A%22actions-ux-201012%22%2C%22operator%22%3A%22icontains%22%2C%22type%22%3A%22event%22%7D%5D).

## Environment

Cloud latest version.


#### *Thank you* for your bug report – we love squashing them!

CC @timgl 

ee/clickhouse/models/action.py
params = {"team_id": action.team.pk}
    steps = action.steps.all()
    if len(steps) == 0:
        
        return "1=2", {}
    or_queries = []
    for index, step in enumerate(steps):
        conditions: List[str] = []
        
        if step.event == AUTOCAPTURE_EVENT:
            el_conditions, element_params = filter_element(step, "{}{}".format(index, prepend))
            params = {**params, **element_params}
            conditions += el_conditions
        
        event_conditions, event_params = filter_event(step, "{}{}".format(index, prepend), index)
        params = {**params, **event_params}
        conditions += event_conditions
        if step.properties:
            from ee.clickhouse.models.property import parse_prop_clauses
            prop_query, prop_params = parse_prop_clauses(
                Filter(data={"properties": step.properties}).properties, action.team.pk
            )
            conditions.append(prop_query.replace("AND", "", 1))
            params = {**params, **prop_params}
        if len(conditions) > 0: