## 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/queries/test/test_trends.py
from uuid import uuid4
from freezegun import freeze_time
from ee.clickhouse.models.event import create_event
from ee.clickhouse.queries.trends.clickhouse_trends import ClickhouseTrends
from ee.clickhouse.util import ClickhouseTestMixin
from posthog.models.action import Action
from posthog.models.action_step import ActionStep
from posthog.models.cohort import Cohort
from posthog.models.filters import Filter
from posthog.models.person import Person
from posthog.queries.test.test_trends import trend_test_factory
def _create_action(**kwargs):
    team = kwargs.pop("team")
    name = kwargs.pop("name")
    action = Action.objects.create(team=team, name=name)
    ActionStep.objects.create(action=action, event=name)
    return action
def _create_cohort(**kwargs):
    team = kwargs.pop("team")
    name = kwargs.pop("name")
    groups = kwargs.pop("groups")
    cohort = Cohort.objects.create(team=team, name=name, groups=groups)
    return cohort
def _create_event(**kwargs):
    kwargs.update({"event_uuid": uuid4()})
    create_event(**kwargs)
class TestClickhouseTrends(ClickhouseTestMixin, trend_test_factory(ClickhouseTrends, _create_event, Person.objects.create, _create_action, _create_cohort)):