add fingerprint for privateIpv6GoogleAccess (#4424) (#2898)

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/4424.txt

@@ -0,0 +1,4 @@
+```release-note:bug
+compute: added fingerprint on private_ipv6_google_access for `google_compute_subnetwork`
+
+```

google-beta/resource_compute_subnetwork.go

@@ -617,6 +617,23 @@ func resourceComputeSubnetworkUpdate(d *schema.ResourceData, meta interface{}) e
 	if d.HasChange("private_ipv6_google_access") {
 		obj := make(map[string]interface{})
 
+		getUrl, err := replaceVars(d, config, "{{ComputeBasePath}}projects/{{project}}/regions/{{region}}/subnetworks/{{name}}")
+		if err != nil {
+			return err
+		}
+
+		// err == nil indicates that the billing_project value was found
+		if bp, err := getBillingProject(d, config); err == nil {
+			billingProject = bp
+		}
+
+		getRes, err := sendRequest(config, "GET", billingProject, getUrl, userAgent, nil)
+		if err != nil {
+			return handleNotFoundError(err, d, fmt.Sprintf("ComputeSubnetwork %q", d.Id()))
+		}
+
+		obj["fingerprint"] = getRes["fingerprint"]
+
 		privateIpv6GoogleAccessProp, err := expandComputeSubnetworkPrivateIpv6GoogleAccess(d.Get("private_ipv6_google_access"), d, config)
 		if err != nil {
 			return err