Ability to configure serviceAccountName on core & replicant pods

[mariusstaicu]

Is your feature request related to a problem? Please describe.
We use emqx with postgres on cloud-sql. At the moment the cloudsql service account key file is mounted to the pods that require it and it works. However, we would very much like to switch to workload identity and it requires defining a service account on pods.

Describe the solution you'd like
The coreTemplateSpec and replicantTemplateSpec should have the possbility of defining serviceAccountName.

Describe alternatives you've considered
Not sure there is any with the current operator API v2alpha1.

Additional context

[Rory-Z]

Good idea！We will finish it，thanks

[Rory-Z]

EMQX Operator 2.2.0 is released, close this issue

[mariusstaicu]

great news, thanks