Using maven, update circleci cli split sentence in the example

[dariocazas]

Description

The split sentence don't work well, copy from the Gradle example run fine https://circleci.com/docs/2.0/language-java/#sample-configuration

Reasons

The previous circleci split sentence return this error:

Error autodetecting timing type, falling back to weighting by name. Autodetect no matching filename or classname.  If file names are used, double check paths for absolute vs relative.