Fix code block markdown in gradle packages doc

[yutailang0119]

Why:

I find code block markdown break in Configuring Gradle for use with GitHub Packages

What's being changed:

before	after

Check off the following:

• All of the tests are passing.
• I have reviewed my changes in staging.
• For content changes, I have reviewed the localization checklist
• For content changes, I have reviewed the Content style guide for GitHub Docs.

[welcome]

Thanks for opening this pull request! A GitHub docs team member should be by to give feedback soon. In the meantime, please check out the contributing guidelines.

[runleonarun]

Hello @yutailang0119! Thank you for proposing a pull request for fixing this problem. We are overjoyed by the help we've been receiving from the community. 💟

Because this particular issue has been fixed by the GitHub Docs team, I am going to close this pull request. We encourage folks to open an issue first so we can verify the need for the proposed change and avoid duplicate work.

[yutailang0119]

Thank you for comment!
I confirmed that it was fixed with #273 .
Thanks! ✨