* The metadata for artifactPrepareVersion-go specifies a container for when the buildTool is maven.
* The alias to 'mavenExecute' was removed. The problem with this is that when a section containers is included in the metadata, dockerImage will always be picked up from mavenExecute, the conditional dependency on buildTool will not even be considered. Parameters such as m2Path, projectSettingsFile and globalSettingsFile should be configured in general/maven if necessary.
* When the step ends up being executed within dockerExecuteOnKubernetes, we need to preserve the .git folder. This folder would normally be excluded by the default excludes of the stash step. There was already a comment that suppressing this behavior by passing useDefaultExcludes: false was problematic (unfortunately without going into details), so I've added a new parameter to dockerExecute and dockerExecuteOnKubernetes named stashNoDefaultExcludes (note the reverted meaning to ease preserving the default behavior when this parameter is not provided). This parameter is passed to piperExecuteBin from the artifactPreferVersion groovy wrapper.
This change enables the use of the artifactPrepareVersion go step instead
of the deprecated artifactSetVersion groovy implementation for the Cloud
SDK Pipeline. The groovy wrapper for the artifactPrepareVersion step now
enables the use of the download cache and minor issues are fixed.
