Revert changes from the lifecycle added for the abrupt termination

[Rushikesh Bankar (rbankar7)]

reverts changes in the lifecycle added by the PR- #341

Description

• The changes were added to make the termination ungraceful when we set the system property druid.lifecycle.ungracefulShutDownWaitTimeExperimental
• But it is not needed now as we have finished our testing

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.