resource/aws_efs_file_system: Refactor tagging to standardized TagRes…

…ource/UntagResource calls, SDK constants, and tests (#11654)

Output from acceptance testing in AWS Commercial:

```
--- PASS: TestAccAWSEFSFileSystem_kmsConfigurationWithoutEncryption (25.32s)
--- PASS: TestAccAWSEFSFileSystem_pagedTags (45.14s)
--- PASS: TestAccAWSEFSFileSystem_ThroughputMode (53.13s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy (67.97s)
--- PASS: TestAccAWSEFSFileSystem_basic (70.60s)
--- PASS: TestAccAWSEFSFileSystem_kmsKey (75.09s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy_removal (80.93s)
--- PASS: TestAccAWSEFSFileSystem_disappears (85.33s)
--- PASS: TestAccAWSEFSFileSystem_ProvisionedThroughputInMibps (106.19s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy_update (127.86s)
--- PASS: TestAccAWSEFSFileSystem_tags (128.90s)
```

Output from acceptance testing in AWS GovCloud (US) (unrelated test failure fix noted in the review):

```
--- PASS: TestAccAWSEFSFileSystem_kmsConfigurationWithoutEncryption (24.79s)
--- FAIL: TestAccAWSEFSFileSystem_basic (27.99s)
--- PASS: TestAccAWSEFSFileSystem_disappears (30.58s)
--- PASS: TestAccAWSEFSFileSystem_kmsKey (49.76s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy_removal (53.12s)
--- PASS: TestAccAWSEFSFileSystem_tags (62.95s)
--- PASS: TestAccAWSEFSFileSystem_ProvisionedThroughputInMibps (81.86s)
--- PASS: TestAccAWSEFSFileSystem_ThroughputMode (87.62s)
--- PASS: TestAccAWSEFSFileSystem_pagedTags (90.78s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy (117.45s)
--- PASS: TestAccAWSEFSFileSystem_lifecyclePolicy_update (123.65s)
```

aws/internal/keyvaluetags/generators/updatetags/main.go

@@ -333,8 +333,6 @@ func ServiceTagFunction(serviceName string) string {
 		return "AddTagsToResource"
 	case "ec2":
 		return "CreateTags"
-	case "efs":
-		return "CreateTags"
 	case "elasticache":
 		return "AddTagsToResource"
 	case "elasticbeanstalk":
@@ -424,7 +422,7 @@ func ServiceTagInputIdentifierField(serviceName string) string {
 	case "ec2":
 		return "Resources"
 	case "efs":
-		return "FileSystemId"
+		return "ResourceId"
 	case "elasticache":
 		return "ResourceName"
 	case "elasticsearchservice":
@@ -577,8 +575,6 @@ func ServiceUntagFunction(serviceName string) string {
 		return "RemoveTagsFromResource"
 	case "ec2":
 		return "DeleteTags"
-	case "efs":
-		return "DeleteTags"
 	case "elasticache":
 		return "RemoveTagsFromResource"
 	case "elasticbeanstalk":

aws/resource_aws_efs_file_system.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/arn"
-	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/service/efs"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/resource"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
@@ -263,7 +262,7 @@ func resourceAwsEfsFileSystemRead(d *schema.ResourceData, meta interface{}) erro
 		FileSystemId: aws.String(d.Id()),
 	})
 	if err != nil {
-		if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "FileSystemNotFound" {
+		if isAWSErr(err, efs.ErrCodeFileSystemNotFound, "") {
 			log.Printf("[WARN] EFS file system (%s) could not be found.", d.Id())
 			d.SetId("")
 			return nil
@@ -275,16 +274,6 @@ func resourceAwsEfsFileSystemRead(d *schema.ResourceData, meta interface{}) erro
 		return fmt.Errorf("EFS file system %q could not be found.", d.Id())
 	}
 
-	tags, err := keyvaluetags.EfsListTags(conn, d.Id())
-
-	if err != nil {
-		return fmt.Errorf("error listing tags for EFS file system (%s): %s", d.Id(), err)
-	}
-
-	if err := d.Set("tags", tags.IgnoreAws().Map()); err != nil {
-		return fmt.Errorf("error settings tags: %s", err)
-	}
-
 	var fs *efs.FileSystemDescription
 	for _, f := range resp.FileSystems {
 		if d.Id() == *f.FileSystemId {
@@ -314,6 +303,10 @@ func resourceAwsEfsFileSystemRead(d *schema.ResourceData, meta interface{}) erro
 	d.Set("provisioned_throughput_in_mibps", fs.ProvisionedThroughputInMibps)
 	d.Set("throughput_mode", fs.ThroughputMode)
 
+	if err := d.Set("tags", keyvaluetags.EfsKeyValueTags(fs.Tags).IgnoreAws().Map()); err != nil {
+		return fmt.Errorf("error setting tags: %s", err)
+	}
+
 	region := meta.(*AWSClient).region
 	if err := d.Set("dns_name", resourceAwsEfsDnsName(aws.StringValue(fs.FileSystemId), region)); err != nil {
 		return fmt.Errorf("error setting dns_name: %s", err)
@@ -363,8 +356,7 @@ func waitForDeleteEfsFileSystem(conn *efs.EFS, id string, timeout time.Duration)
 				FileSystemId: aws.String(id),
 			})
 			if err != nil {
-				efsErr, ok := err.(awserr.Error)
-				if ok && efsErr.Code() == "FileSystemNotFound" {
+				if isAWSErr(err, efs.ErrCodeFileSystemNotFound, "") {
 					return nil, "", nil
 				}
 				return nil, "error", err