Ignoring the case for NSG Protocol's in the state (#13153)

builtin/providers/azurerm/resource_arm_network_security_group.go

@@ -66,6 +66,7 @@ func resourceArmNetworkSecurityGroup() *schema.Resource {
 							Type:         schema.TypeString,
 							Required:     true,
 							ValidateFunc: validateNetworkSecurityRuleProtocol,
+							StateFunc:    ignoreCaseStateFunc,
 						},
 
 						"source_port_range": {

builtin/providers/azurerm/resource_arm_network_security_group_test.go

@@ -204,7 +204,7 @@ resource "azurerm_network_security_group" "test" {
     	priority = 100
     	direction = "Inbound"
     	access = "Allow"
-    	protocol = "Tcp"
+    	protocol = "TCP"
     	source_port_range = "*"
     	destination_port_range = "*"
     	source_address_prefix = "*"