This is readily available in the head of the repository so this issue can be closed. Note that changing existing logging configurations sometimes does not take effect due to issues on the Google Storage side. I was told this will be fixed in about a week.
I found a signature-generate bug when setting bucket logging status for Google storage, this is now fixed (see above).
You can get an idea of how to set bucket logging status for GS by looking at the new tests in the fix changeset, the code is messy since it's exercising both S3 and GS services but it gives at least a general idea.