Implement a include_git_properties_file attribute

[plaird]

We enable build stamping for our production builds, which writes Git coordinates into a git.properties file in the Spring Boot jar. This explains it:

https://github.com/salesforce/rules_spring/blob/main/tools/buildstamp/README.md

But we have a situation where we need to always disable it for reasons ("security") for a small set of Spring Boot jars. Instead of implementing conditional logic in our CI pipleline, it would be nice to just have an attribute in the rule:

springboot(
 ...
 include_git_properties_file = False,
)