Update validate-modules (#20932)

* Update validate-modules

* Validates ANSIBLE_METADATA
* Ensures imports happen after documentation vars
* Some pep8 cleanup

* Clean up some left over unneeded code

* Update modules for new module guidelines and validate-modules checks

* Update imports for ec2_vpc_route_table and ec2_vpc_nat_gateway

lib/ansible/modules/cloud/amazon/ec2_vpc_nat_gateway.py

@@ -14,18 +14,6 @@
 # You should have received a copy of the GNU General Public License
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
-# import module snippets
-from ansible.module_utils.basic import AnsibleModule
-from ansible.module_utils.ec2 import ec2_argument_spec, get_aws_connection_info, boto3_conn
-
-import datetime
-import random
-import re
-import time
-
-from dateutil.tz import tzutc
-
-
 ANSIBLE_METADATA = {'status': ['preview'],
                     'supported_by': 'community',
                     'version': '1.0'}
@@ -221,6 +209,16 @@ nat_gateway_addresses:
   ]
 '''
 
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.ec2 import ec2_argument_spec, get_aws_connection_info, boto3_conn
+
+import datetime
+import random
+import re
+import time
+
+from dateutil.tz import tzutc
+
 try:
     import botocore
     import boto3
@@ -228,7 +226,6 @@ try:
 except ImportError:
     HAS_BOTO3 = False
 
-
 DRY_RUN_GATEWAYS = [
     {
         "nat_gateway_id": "nat-123456789",