When a binding of type or kind equals `gradle` is present, the contents of that file are copied to `$GRADLE_USER_HOME/gradle.properties`. This is picked up by Gradle when it runs and allows the user to pass additional configuration to Gradle. For example, this can be used for providing credentials to a remote Maven repository.

…d of copying it into the layer

Co-authored-by: Emily Casey <ecasey@vmware.com>

…r to the layer where gradle runs, but after the cache layer. This allows the cache code to run and initialize the symlink for the cache, then this layer contributes next, adding the symlink into the cache directory and finally gradle runs.