To work with Git, the Git plugin (version 1.1.10 or later) has to be configured to build one branch AND to checkout to the same local branch. The remote URL should allow Read+Write access.
The plugin uses the git client installed on the machine and uses its credentials to push back to the remote Git repository.
During the release the plugin will perform the following:
If create branch is checked, create and switch to the release branch
Commit the release version to the current branch
Create a release tag
Push the changes
Switch to the checkout branch and commit the next development version
Push the next development version to the working branch
Note that changes will only be committed if changes were made to the files (pom files or gradle.properties)