r/aws_emr_instance_group: Properly send an instance_count value of 0 on create when configured.

Author: ewbankkit

.changelog/37740.txt

@@ -8,4 +8,8 @@ resource/aws_emr_instance_fleet: Support `io2` as a valid value for `instance_ty
 
 ```release-note:enhancement
 resource/aws_emr_instance_group: Support `io2` as a valid value for `instance_type_configs.ebs_config.type`
+```
+
+```release-note:bug
+resource/aws_emr_instance_group: Properly send an `instance_count` value of `0` on create when configured
 ```

internal/service/emr/instance_group.go

@@ -185,8 +185,9 @@ func resourceInstanceGroupCreate(ctx context.Context, d *schema.ResourceData, me
 		}
 	}
 
-	if v, ok := d.GetOk(names.AttrInstanceCount); ok {
-		groupConfig.InstanceCount = aws.Int32(int32(v.(int)))
+	if v := d.GetRawConfig().GetAttr(names.AttrInstanceCount); v.IsKnown() && !v.IsNull() {
+		v, _ := v.AsBigFloat().Int64()
+		groupConfig.InstanceCount = aws.Int32(int32(v))
 	} else {
 		groupConfig.InstanceCount = aws.Int32(1)
 	}