Some time ago, ExtraMounts parameter has been introduced to test-operator [1]. This means that ExtraConfigmapsMounts __ is duplicate that could be removed, as config maps can be specified using ExtraMounts. This will not be as simple as removing the code from test-operator, there is a bigger research needed on how many use cases does the ExtraConfigmapsMounts parameter have.

[1] https://github.com/openstack-k8s-operators/test-operator/pull/283