What is the purpose of the change

This pull request relaxes the restriction on multiple jobs in HA mode, allowing an application to submit more than one batch job. It also removes the restriction to support cases where no jobs need to be submitted.

Brief change log

• Update the job count limit validation logic in StreamContextEnvironment to support multiple jobs
• Update the JarRunApplicationHandler and ApplicationDispatcherGatewayServiceFactory to enable submission of multiple batch jobs in HA mode
• Update the PackagedProgramApplication to allow applications with no jobs

Verifying this change

This change added tests and can be verified as follows:

• Added tests for PackagedProgramApplication to validate multiple job support

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (yes)
• If yes, how is the feature documented? (docs)