Update autolabeler config to match any file with gradle in it

[kbendick]

As noticed in this PR, #1423, changes to the build.gradle file were not properly handled by the autolabeler.

I have updated the autolabeler config to handle this case. I've also merged this into my local repo in order to test for this.

I validated the change on a top level file named gradle.properties (to check both top level files as well as files with only the substing gradle) in this PR in my local repo.

I also tested against the build.gradle file, as that was the original file and it differed from the previous one in that gradle is now the ending substring (checking padding on either side).

I also performed two checks for files in the gradle directory, one that checks on a file with gradle in the name and one that checks solely on a change that matches the gradle dir in the path, with no gradle in the file name.

Suffice it to say that this has ben pretty pedantically checked 😅 .

This PR closes this issue: #1447

cc @rdblue who noticed that the file didn't match. Thank you for that!

[kbendick]

For anybody who looked at the demo PRs in my peronal repo, notw that 've already overwritten the master branch to match the apache master. In order for the tags to be applied, the autolabeler config needs to be updated first and then changes will show up (they can't typically be intermixed in the same PR like the PRs in my personal repo make it look).

[rdblue]

Thanks, @kbendick!

[kbendick]

Thanks, @kbendick!

No problem. Thank you for noticing this bug and tagging me!