* Allow to use selectors with volumeClaimTemplates
* Fixed naming inconsistency, added null value
Co-authored-by: Claudio Vellage <claudio.vellage@pm.me>
Co-authored-by: Michael Marshall <mmarshall@apache.org>
### Motivation
Currently it's not possible to use selectors with volumeClaimTemplates which makes it hard/impossible to bind statically provisioned PVs.
### Modifications
Added (optional) selectors to `volumeClaimTemplates` and documented in values file.
### Verifying this change
- [ ] Make sure that the change passes the CI checks.