allow specifying ingressClass in values.yaml

[gjacobsatl]

It'd be handy to be able to specify ingressClass via values.yaml.

[jimmy-ungerman]

Opened a PR for this here

[mmcclaskey]

Thank you! We are in the middle of getting a 1.16.1 update done, but I will get that in shortly. I think we have an overlapping internal merge request that does the same, so you may see this PR closed depending on which one is selected.

[jimmy-ungerman]

@mmcclaskey sounds good! Just want to help in any way I can