Fix for default_tags and tags on EC2 block devices

`default_tags` support for EC2 root block devices was introduced in
hasicorp/terraform-provider-aws#33769, which is great ... except it
makes the mix of `default_tags` and `tags` on a `root_block_device`
perpetually showing drift even when there is none.

The solution is to not remove the default tags config from the volume
tags in ec2_instance.

This diff fixes #36448 for us in our
environment (which references #33769 as
the change that introduced this bug).

This diff possibly fixes #36706 too, but
we weren't hitting this issue.

internal/service/ec2/ec2_instance.go

@@ -1331,11 +1331,10 @@ func resourceInstanceRead(ctx context.Context, d *schema.ResourceData, meta inte
 			return sdkdiag.AppendErrorf(diags, "reading EC2 Instance (%s): %s", d.Id(), err)
 		}
 
-		defaultTagsConfig := meta.(*conns.AWSClient).DefaultTagsConfig
 		ignoreTagsConfig := meta.(*conns.AWSClient).IgnoreTagsConfig
 		tags := keyValueTags(ctx, volumeTags).IgnoreAWS().IgnoreConfig(ignoreTagsConfig)
 
-		if err := d.Set("volume_tags", tags.RemoveDefaultConfig(defaultTagsConfig).Map()); err != nil {
+		if err := d.Set("volume_tags", tags.Map()); err != nil {
 			return sdkdiag.AppendErrorf(diags, "setting volume_tags: %s", err)
 		}
 	}
@@ -2319,7 +2318,6 @@ func readBlockDevicesFromInstance(ctx context.Context, d *schema.ResourceData, m
 		return nil, err
 	}
 
-	defaultTagsConfig := meta.(*conns.AWSClient).DefaultTagsConfig
 	ignoreTagsConfig := meta.(*conns.AWSClient).IgnoreTagsConfig
 
 	for _, vol := range volResp.Volumes {
@@ -2357,7 +2355,7 @@ func readBlockDevicesFromInstance(ctx context.Context, d *schema.ResourceData, m
 				bd[names.AttrTags] = keyValueTags(ctx, vol.Tags).IgnoreAWS().IgnoreConfig(ignoreTagsConfig).Map()
 			} else {
 				tags := keyValueTags(ctx, vol.Tags).IgnoreAWS().IgnoreConfig(ignoreTagsConfig)
-				bd[names.AttrTags] = tags.RemoveDefaultConfig(defaultTagsConfig).Map()
+				bd[names.AttrTags] = tags.Map()
 				bd[names.AttrTagsAll] = tags.Map()
 			}
 		}