add manifest/3.2.xml back to product-config.json as a disabled entry.

[mhocouchbase]

Describe your PR here...

currently, build-from-manifest-new keeps triggering manifest/3.2.xml and manifest/default.xml. Since both are 3.2.0, it causes https://github.com/couchbase/build-manifests/blob/master/sync_gateway/3.2.0/3.2.0.xml to be different on every scan. This results in a new build on every single scan. Having a disabled manifest/3.2.xml entry should stop "manifest/3.2.xml" from getting triggered.

-Ming

Pre-review checklist

• Removed debug logging (fmt.Print, log.Print, ...)
• Logging sensitive data? Make sure it's tagged (e.g. base.UD(docID), base.MD(dbName))
• Updated relevant information in the API specifications (such as endpoint descriptions, schemas, ...) in docs/api

Dependencies (if applicable)

• Link upstream PRs
• Update Go module dependencies when merged

Integration Tests

• GSI=true,xattrs=true https://jenkins.sgwdev.com/job/SyncGateway-Integration/000/