Allow add persitentVolumeClaim to filer when using embedded Filer Store

[raulpuente]

It would be great to configure a PersistentVolumeClaim for filer store on filer stafulset . Because if all the filer stops for any reason all the data on, for example, LevelDB will disappear.

[chrislusf]

Agree! Do you want to send a PR?

[raulpuente]

Ok!, i will do it!, Do you prefer to add fields on the same version of the api api/v1 or to generate new version api/v2?

[jessebot]

@chrislusf know you're really busy and pulled in a lot of different directions, but could you answer the question above?

[chrislusf]

I actually don't know. Maybe it's good to do both?

[jessebot]

Thanks! @raulpuente let me know if you'd like to rubberduck on this. This is a feature I'm also interested in :)