fix bug when google_compute_region_disk_resource_policy_attachment is empty, it errored (#3499)
fix bug when google_compute_region_disk_resource_policy_attachment is empty, it errored (#3499)


GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules