Grafana 7.x is not installing unsigned community plugins

[unintended]

After upgrade to a newer version Clickhouse plugin is no longer available (https://grafana.com/grafana/plugins/vertamedia-clickhouse-datasource?src=grafana_plugin_list)

New env variable introduced to allow loading of unsigned plugins (see https://grafana.com/grafana/plugins/vertamedia-clickhouse-datasource?src=grafana_plugin_list):
GF_PLUGINS_ALLOW_LOADING_UNSIGNED_PLUGINS=vertamedia-clickhouse-datasource
but GF_INSTALL_PLUGINS is still used.

What happened?
Clickhouse plugin is not installed

Did you expect to see some different?
Clickhouse plugin to be installed

How to reproduce it (as minimally and precisely as possible):
Add this to the config and generate a deployment:

grafana+:: {
      plugins: ['vertamedia-clickhouse-datasource']
}

Originally from prometheus-operator/kube-prometheus#807

[brancz]

I think people should do this consciously, so I would suggest adding a new variable to specifically allow unsigned plugins. What do you think?

[unintended]

I suppose it's ok to add a separate variable for this

[brancz]

Do you want to contribute this? :)