Is your feature request related to a problem? Please describe.

Oracle provider can only use pod service account for authentication using workload identity. It should support any valid service account token.

Describe the solution you'd like

Add serviceAccountRef *esmeta.ServiceAccountSelector field to the Oracle provider. If this field is specified, use that service account instead of the pod service account for workload identity authentication.

Describe alternatives you've considered
n/a

Additional context
n/a