HADOOP-19661. (Follow-up) Rename Dockerfile_centos_8 to Dockerfile_rockylinux_8

[pan3793]

JIRA: HADOOP-19661. (Follow-up) Rename Dockerfile_centos_8 to Dockerfile_rockylinux_8.

I have to keep the Dockerfile name to bypass Yetus issue, see discussion in #7900

But should rename it back before committing to trunk, since the thing has already happened, send a followup to fix it.

[pan3793]

@cnauroth

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 0s		Docker mode activated.
-1 ❌	docker	0m 21s		Dockerfile '/home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-7917/rockylinux-8/src/dev-support/docker/Dockerfile_rockylinux_8' not found.

Subsystem	Report/Notes
GITHUB PR	#7917
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7917/1/console
versions	git=2.34.1
Powered by	Apache Yetus 0.14.0 https://yetus.apache.org

This message was automatically generated.

[pan3793]

no need to wait for Yetus's report since Yetus will fail with Dockerfile_rockylinux_8 not found immediately

[slfan1989]

@cnauroth I suggest waiting for a day to see if tomorrow's auto-build email triggers RockyLinux_8 completely. If it doesn't trigger properly, we'll look for a solution.

cc: @pan3793

[slfan1989]

@cnauroth I suggest waiting for a day to see if tomorrow's auto-build email triggers RockyLinux_8 completely. If it doesn't trigger properly, we'll look for a solution.

cc: @pan3793

@cnauroth @pan3793

After offline discussion with Pan, we've decided to merge this PR for now. If any issues arise, we'll make updates accordingly.