Add update API for instance GCP audit event destinations

What does this MR do and why?

1. This MR adds an GraphQL update API for instance level GCP audit event destinations.
2. A concern CommonUpdate is added for containing common code of group level and instance level update mutations.

Query plan

Query:

https://console.postgres.ai/gitlab/gitlab-production-tunnel-pg12/sessions/22849/commands/73715

UPDATE 
  "audit_events_instance_google_cloud_logging_configurations" 
SET 
  "updated_at" = '2023-10-04 16:31:13.005842', 
  "google_project_id_name" = 'updated-project', 
  "client_email" = 'updated-email@example.com', 
  "log_id_name" = 'updated_log_id_name', 
  "name" = 'updated_destination_name', 
  "encrypted_private_key" = 'some_private_key', 
  "encrypted_private_key_iv" = 'some_private_key_iv' 
WHERE 
  "audit_events_instance_google_cloud_logging_configurations"."id" = 9

How to set up and validate locally

1. For this you need to have admin access of a GitLab instance with an Ultimate license.
2. Visit graphql explorer https://gitlab.localdev:3000/-/graphql-explorer.
3. Run following mutation to add new instance level gcp configuration

mutation instanceGoogleCloudLoggingConfigurationCreate {
  instanceGoogleCloudLoggingConfigurationCreate(input: { googleProjectIdName: "my-google-project", clientEmail: "my-email@my-google-project.iam.gservice.account.com", privateKey: "YOUR_PRIVATE_KEY", logIdName: "audit-events", name: "my-destination" }) {
    errors
    instanceGoogleCloudLoggingConfiguration {
      id
      logIdName
      googleProjectIdName
      clientEmail
      name
    }
  }
}

4. For credentials you can refer to details in https://docs.gitlab.com/ee/administration/audit_event_streaming/#google-cloud-logging-destinations. But for now dummy details will also work. I will enable streaming for this in another MR which belongs to issue #423041 (closed).
5. For checking if the configuration got added or not you can run following query for listing the details

query instanceGoogleCloudLoggingConfigurations {
  instanceGoogleCloudLoggingConfigurations {
    nodes {
        id
        logIdName
        googleProjectIdName
        clientEmail
        name
      }
  }
}

6. Now run following mutation to update the configuration, use the id received in step 5, it should update the config

mutation instanceGoogleCloudLoggingConfigurationUpdate {
  instanceGoogleCloudLoggingConfigurationUpdate(
    input: {id: "gid://gitlab/AuditEvents::Instance::GoogleCloudLoggingConfiguration/11", googleProjectIdName: "updated-google-id", clientEmail: "updatedl@my-google-project.iam.gservice.account.com", privateKey: "YOUR_PRIVATE_KEY", logIdName: "audit-events", name: "updated name"}
  ) {
    errors
    instanceGoogleCloudLoggingConfiguration {
      id
      logIdName
      googleProjectIdName
      clientEmail
    }
  }
}

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #423039 (closed)