Variable interpolation with 'IN' clause for POSTGRES DB

Grafana version: 7.4.3
I am trying to write a query with ‘IN’ clause to create chart based on multi value selection filter. I used following query with variable interpoloation:
‘’’
SELECT
__time(timestamp), hostname as metric, avg((metrics->'memory'->'HeapMemoryUsage'->>'used')::bigint)as value FROM public.metrics WHERE __timeFilter(timestamp) and hostname in (’${hostList:csv}’)
group by time, hostname
order by time
‘’’
Expected result:
‘’’
SELECT
timestamp AS “time”,
hostname as metric,
avg((metrics->‘memory’->‘HeapMemoryUsage’->>‘used’)::bigint)as value
FROM
public.metrics
WHERE
timestamp BETWEEN ‘2021-03-04T21:34:15.371Z’ AND ‘2021-03-05T21:34:15.371Z’ and hostname in (‘a’, ‘b’, ‘c’)
group by timestamp, hostname
‘’’
What I get is:
‘’’
SELECT
timestamp AS “time”,
hostname as metric,
avg((metrics->‘memory’->‘HeapMemoryUsage’->>‘used’)::bigint)as value
FROM
public.metrics
WHERE
timestamp BETWEEN ‘2021-03-04T21:34:15.371Z’ AND ‘2021-03-05T21:34:15.371Z’ and hostname in (‘a, b, c’)
group by timestamp, hostname
‘’’

Use better variable formatting, singlequote in your case and not csv.