[MRELEASE-1004] preparationGoals scm:checkin goal comma separated list does not work

**[Aruna Herath](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=roonyh)** opened **[MRELEASE-1004](https://issues.apache.org/jira/browse/MRELEASE-1004?redirect=false)** and commented

I am specifying an array of files to be committed before the release plugin commits poms.

```xml

org.apache.maven.plugins
maven-release-plugin
2.5.4


clean verify scm:checkin -Dmessage="[maven-release-plugin] Update version text" -Dincludes="tool-plugins/vscode/package.json, tool-plugins/vscode/package-lock.json"

```

But this ends up commiting all the files including the poms, not just `package.json` and `package-lock.json`. When its just one file instead of a comma seperated list it works (just commits the specified file)
 
`scm:checkin` goal with above arguments works when specified directly. It only does not work when specified in `preparationGoals`.

---
No further details from [MRELEASE-1004](https://issues.apache.org/jira/browse/MRELEASE-1004?redirect=false)

Reproduce the Maven release plugin configuration shown in the issue, comparing scm:checkin invoked directly with the same goal in preparationGoals. The fix is complete when a comma-separated -Dincludes list in preparationGoals commits only the specified files, matching direct invocation behavior.

Written by the indexing model from the issue text.