Made firewall policy with rules ignore decoding operations on create (#13651) (#9776)

[upstream:9a5c4ebb5e9df0236bc5bc127fbd6a457690c89e]

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

Author: modular-magician

google-beta/services/compute/resource_compute_firewall_policy_with_rules.go

@@ -1819,6 +1819,11 @@ func resourceComputeFirewallPolicyWithRulesUpdateEncoder(d *schema.ResourceData,
 }
 
 func resourceComputeFirewallPolicyWithRulesDecoder(d *schema.ResourceData, meta interface{}, res map[string]interface{}) (map[string]interface{}, error) {
+	// If rules is nil, this is being called on a Create operation (and we don't want to do anything in that case.)
+	if _, ok := res["rules"]; !ok {
+		return res, nil
+	}
+
 	rules, predefinedRules, err := firewallPolicyWithRulesSplitPredefinedRules(res["rules"].([]interface{}))
 
 	if err != nil {