add isPlain modifier as follow up to https://github.com/patternfly/patternfly/issues/8106 if isPlain={false} add a 'pf-m-no-plain' modifier --- **Jira Issue:** [PF-3732](https://redhat.atlassian.net/browse/PF-3732)
add isPlain modifier as follow up to patternfly/patternfly#8106
if isPlain={false} add a 'pf-m-no-plain' modifier
Jira Issue: PF-3732