🐛 Avoid setting values to nil on GCP logging resource

[arlimus]

Fixes #1931

[czunker]

Looking better now:

cnquery run gcp project mondoo-dev-262313 -c "gcp.project.logging.sink{*}" 
→ loaded configuration from /etc/opt/mondoo/mondoo.yml using source default
1 error occurred:
	* cannot convert primitive with NO type information
gcp.project.loggingservice.sink: {
  includeChildren: cannot convert primitive with NO type information
  projectId: cannot convert primitive with NO type information
  id: cannot convert primitive with NO type information
  storageBucket: null
  filter: cannot convert primitive with NO type information
  writerIdentity: cannot convert primitive with NO type information
  destination: cannot convert primitive with NO type information
}

The "cannot convert" messages will be addressed with #1943

[czunker]

Thanks @arlimus