Fix: NetworkPolicies for custom grpc rules

[m-rcl]

as stated in #24 it's not possible to use networkPolicies with custom grpc rules.
PR #297 seems to be stale and the proposed solution renders strangely for the default of grpc (empty array).

This PR renders

networkPolicy:
  enabled: true
  ingress:
    grpc:
    - podSelector:
        matchLabels:
          app.kubernetes.io/instance: foo

into

[...]
  ingress:
    - ports:
        - port: grpc
      from:
        # Allow connections via custom rules.
        - podSelector:
            matchLabels:
              app.kubernetes.io/instance: foo
        # Allow client connection via pre-considered label.
        - podSelector:
            matchLabels:
[...]

and

networkPolicy:
  enabled: true
# leave grpc as empty array

into

[...]
  ingress:
    - ports:
        - port: grpc
      from:
        # Allow client connection via pre-considered label.
        - podSelector:
            matchLabels:
[...]

[m-rcl]

Hi @prafull01, any chance we might get this merged soon?

[m-rcl]

Hi @rail, is there anyone else who might have a look at this PR?

[m-rcl]

@rail @prafull01 - any update?

[m-rcl]

@rail @prafull01 - This is still an issue with the lastest 14.0.5 chart. Any chance we might get this minor fix solved soon?
@udnay - Maybe you could have a look?

[m-rcl]

@rail @prafull01 - Can we please have this reviewed? It's pending for almost a year now