Wrong default JDBC storage type for MySQL deployment

[mecseid]

The Docker images that provide MySQL drivers have the wrong default JDBC storage type.
The related Docker images:

• https://hub.docker.com/r/apicurio/apicurio-studio-ws-mysql
• https://hub.docker.com/r/apicurio/apicurio-studio-api-mysql

I think the APICURIO_DB_TYPE environment variable should be set in the related Dockerfiles (which I didn't find anywhere in this repository) to mysql5 (currently it is postgresql9).

Besides that, the Kubernetes resources and helm templates contain the APICURIO_DB_TYPE, which evaluates at build time, not the preferred APICURIO_HUB_STORAGE_JDBC_TYPE environment variable.