feat(helm): add annotations on ServiceAccount

[gforien]

SUMMARY

We want to add annotations on the Kubernetes ServiceAccount.

How

• Add the field in serviceaccount.yaml template
• Add default empty value in values.yaml
• Update JSON schema
• Bump chart version

TESTING INSTRUCTIONS

helm lint
helm template . superset-release

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API