HDDS-4219. Revisit 'static' nature of OM Layout Version Manager.

[avijayanhwx]

What changes were proposed in this pull request?

• Cleanup of OM and HDDS layout version manager classes.
• Moved away from static initialization for ease of unit testing.
• Renamed SCM and Datanode finalization action for first upgrade version.
• Removed higher level HDDS Layout feature and action catalog classes.
• Combine SCM and Datanode LayoutVersionManager since they are essentially the same.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-4219

How was this patch tested?

Unit testing.

[fapifta]

Hi @avijayanhwx thank you for working on this one, the changes look good to me.

One thing I would note is the missing newline at the end of the HDDSLayoutFeature class, other than that it looks good to me.
+1 otherwise.

[avijayanhwx]

Hi @avijayanhwx thank you for working on this one, the changes look good to me.

One thing I would note is the missing newline at the end of the HDDSLayoutFeature class, other than that it looks good to me.
+1 otherwise.

Thanks for the review @fapifta. Based on offline review, I have further simplified the HDDS actions. PTAL

[fapifta]

+1

[avijayanhwx]

Failed test in CI (TestSCMRestart) was fixed in HDDS-4679.

[swagle]

+1 LGTM, super like the fact that we have moved away from static initializers avoiding need for test instrumentation, we should document best practices for Ozone based on such refactors.

[avijayanhwx]

Thanks for the review @fapifta & @swagle!