Make terminationGracePeriodSeconds configurable

[mucahitkantepe]

We have been using FIAAS to deploy various applications, including Kafka Streams applications, and have noticed that the default terminationGracePeriodSeconds value of 30 seconds is too short for some of our use cases. We have encountered situations where some of our applications, including Kafka Streams, need more time to gracefully shut down and complete any in-flight processing before shutting down.

We believe that allowing users to configure the terminationGracePeriodSeconds value for all applications in FIAAS would be beneficial, as it would provide the flexibility to set an appropriate value based on their specific needs.