Cleanup - use is_boto3_error_(message|code) (ansible-collections#268)

* Reorder imports
* Make use of is_boto3_error_message
* Mass-migration over to is_boto3_error_code
* Remove unused imports
* unused vars in exception
* Improve consistency around catching BotoCoreError and ClientError
* Remove unused imports
* Remove unused 'PolicyError' from iam_policy_info
* Avoid catching botocore.exceptions.ClientError when we only want some error codes
* Import camel_dict_to_snake_dict/snake_dict_to_camel_dict from ansible.module_utils.common.dict_transformations

This commit was initially merged in https://github.com/ansible-collections/community.aws
See: ansible-collections/community.aws@4cf52ef

plugins/modules/ec2_vpc_route_table.py

@@ -226,19 +226,24 @@
 
 import re
 from time import sleep
-from ansible_collections.amazon.aws.plugins.module_utils.core import AnsibleAWSModule
-from ansible_collections.amazon.aws.plugins.module_utils.waiters import get_waiter
-from ansible_collections.amazon.aws.plugins.module_utils.ec2 import ansible_dict_to_boto3_filter_list
-from ansible_collections.amazon.aws.plugins.module_utils.ec2 import camel_dict_to_snake_dict, snake_dict_to_camel_dict
-from ansible_collections.amazon.aws.plugins.module_utils.ec2 import ansible_dict_to_boto3_tag_list, boto3_tag_list_to_ansible_dict
-from ansible_collections.amazon.aws.plugins.module_utils.ec2 import compare_aws_tags, AWSRetry
-
 
 try:
     import botocore
 except ImportError:
     pass  # caught by AnsibleAWSModule
 
+from ansible.module_utils.common.dict_transformations import camel_dict_to_snake_dict
+from ansible.module_utils.common.dict_transformations import snake_dict_to_camel_dict
+
+from ansible_collections.amazon.aws.plugins.module_utils.core import AnsibleAWSModule
+from ansible_collections.amazon.aws.plugins.module_utils.core import is_boto3_error_code
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import ansible_dict_to_boto3_filter_list
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import ansible_dict_to_boto3_tag_list
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import AWSRetry
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import boto3_tag_list_to_ansible_dict
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import compare_aws_tags
+from ansible_collections.amazon.aws.plugins.module_utils.waiters import get_waiter
+
 
 CIDR_RE = re.compile(r'^(\d{1,3}\.){3}\d{1,3}/\d{1,2}$')
 SUBNET_RE = re.compile(r'^subnet-[A-z0-9]+$')
@@ -370,11 +375,8 @@ def ensure_tags(connection=None, module=None, resource_id=None, tags=None, purge
 def describe_route_tables_with_backoff(connection, **params):
     try:
         return connection.describe_route_tables(**params)['RouteTables']
-    except botocore.exceptions.ClientError as e:
-        if e.response['Error']['Code'] == 'InvalidRouteTableID.NotFound':
-            return None
-        else:
-            raise
+    except is_boto3_error_code('InvalidRouteTableID.NotFound'):
+        return None
 
 
 def get_route_table_by_id(connection, module, route_table_id):