clarify comments about project id/name/number.
clarify comments about project id/name/number.

laramiel/fluent-plugin-google-cloud,a-robinson/fluent-plugin-google-cloud,cosmo0920/fluent-plugin-google-cloud,senthilkumar-kj/fluent-plugin-google-cloud,swalkowski/fluent-plugin-google-cloud,GoogleCloudPlatform/fluent-plugin-google-cloud,arthurdarcet/fluent-plugin-google-cloud