Taken the checkstyle report produced by PHP_CodeSniffer (file: phpcs_checkstyle.xml) is transformed in Jenkins version (file: jenkins_checkstyle.xml) when it's been published after build ends.

However during that transformation the content id double-escaped:

1.

"

is transformed into

"

2.

"

is transformed into

"

Original issue posted on PHP_CodeSniffer issue tracker: https://github.com/squizlabs/PHP_CodeSniffer/issues/315

P.S.
Both files are from different builds, so please ignore fact, that warnings don't match.