Make flatteners of sets return sets (#1880)

<!-- This change is generated by MagicModules. -->
/cc @danawillow

google/resource_compute_forwarding_rule.go

@@ -628,7 +628,10 @@ func flattenComputeForwardingRulePortRange(v interface{}) interface{} {
 }
 
 func flattenComputeForwardingRulePorts(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeForwardingRuleSubnetwork(v interface{}) interface{} {

google/resource_compute_route.go

@@ -379,7 +379,10 @@ func flattenComputeRoutePriority(v interface{}) interface{} {
 }
 
 func flattenComputeRouteTags(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeRouteNextHopGateway(v interface{}) interface{} {

google/resource_compute_ssl_policy.go

@@ -399,11 +399,17 @@ func flattenComputeSslPolicyMinTlsVersion(v interface{}) interface{} {
 }
 
 func flattenComputeSslPolicyEnabledFeatures(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeSslPolicyCustomFeatures(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeSslPolicyFingerprint(v interface{}) interface{} {

google/resource_compute_vpn_tunnel.go

@@ -589,11 +589,17 @@ func flattenComputeVpnTunnelIkeVersion(v interface{}) interface{} {
 }
 
 func flattenComputeVpnTunnelLocalTrafficSelector(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeVpnTunnelRemoteTrafficSelector(v interface{}) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+	return schema.NewSet(schema.HashString, v.([]interface{}))
 }
 
 func flattenComputeVpnTunnelLabels(v interface{}) interface{} {