slightly rephrase support level
slightly rephrase support level

Change-Id: I8952929dc076aec2a2f1ebc8085ae0d6094e5695
GitOrigin-RevId: 9d53ddf868aec16c5a228ad515ae18055d288b53

GoogleCloudPlatform/gcpdiag,GoogleCloudPlatform/gcpdiag,GoogleCloudPlatform/gcpdiag