HDDS-3178. Add unit tests for OMGetDelegationToken Request and Response

[cxorm]

What changes were proposed in this pull request?

Proposed change.

• Part for testing OMGetDelegationTokenRequest
  In OMGetDelegationTokenRequest#preExecute, if the Token<OzoneTokenIdentifier> token is not null, we set UpdateGetDelegationTokenRequest with renewInterval and we set GetDelegationTokenResponse with response. So the UT test these items.

  If the Token<OzoneTokenIdentifier> token is null, we do not set GetDelegationTokenResponse with response and UT verified it.

  In OMGetDelegationTokenRequest#validateAndUpdateCache, if the token is not null, we will get OMClientResponse with non "-1" renewTime and UT verified it.

  The UT also tests validateAndUpdateCache with Token<OzoneTokenIdentifier> that causes Exception.

• Part for testing OMGetDelegationTokenResponse
  The UT in this part tests functionality of addToDBBatch .

• Create base classes TestOMDelegationTokenResponse and TestOMDelegationTokenRequest for later used by cancelToken and renewToken.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-3178

How was this patch tested?

Add UTs including

• TestOMGetDelegationTokenRequest
• TestOMGetDelegationTokenResponse

[adoroszlai]

@hanishakoneru since you created the task for this change, may I ask you to review?

[hanishakoneru]

Thank you @cxorm for working on this. Overall LGTM. Just a minor comment.

@bharatviswa504 do you wanna take a quick look as you worked on the DelegationTokenRequests?

[hanishakoneru]

Do we need to set the secretManager again? OzoneManager.getDelegationTokenMgr is going to return the same object again.

[cxorm]

Thank you @hanishakoneru for the review.

Yes, we don't need secretManager here.
Updated.

[hanishakoneru]

LGTM. +1 pending CI.

[cxorm]

Rebase latest master-branch(#839) and trigger github-actions.

[hanishakoneru]

Thanks @cxorm for working on this. I will merge this PR.

[cxorm]

Thanks @hanishakoneru for the merge.