Support for concurrency policy of a Job Schedule

[taxone]

Adding support for concurrency policy of a Job Schedule

The concurrency policy of a job schedule should be specified as an application deployment property or as default server property.

For example, the concurrency policy could be defined for a single application in the deployment properties:

deployer.MySampleApp.kubernetes.cron.concurrencyPolicy=Forbid

Also, a default value could b provided in the server configuration:

    spring:
      cloud:
        dataflow:
          task:
            platform:
              kubernetes:
                accounts:
                  default:
                    cron:
                      concurrencyPolicy: Forbid