##### SUMMARY
If you pass aws_kms an existing key_id and no alias, it throws exceptions

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/modules/cloud/amazon/aws_kms.py

##### ANSIBLE VERSION
```
ansible 2.8.2
  config file = /home/mchappel/.ansible.cfg
  configured module search path = [u'/home/mchappel/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.5 (default, Jun 11 2019, 12:19:05) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]
```

##### CONFIGURATION
```
DEFAULT_CALLBACK_WHITELIST(/home/mchappel/.ansible.cfg) = [u'timer', u'profile_tasks']
DEFAULT_VAULT_IDENTITY_LIST(/home/mchappel/.ansible.cfg) = [u'original@/home/mchappel/.ansible/secrets/original', u'ssl@/home/mchappel/.ansible/secrets/ssl', u'jenkins@/home/mchappel/.ansible/secrets/jenkins']
HOST_KEY_CHECKING(/home/mchappel/.ansible.cfg) = False
RETRY_FILES_ENABLED(/home/mchappel/.ansible.cfg) = False
```

##### OS / ENVIRONMENT
RHEL7

##### STEPS TO REPRODUCE
```
     - name: Update Policy on key to match AWS Console generate policy
       aws_kms:
        key_id: '{{ new_key["keys"][0]["key_id"] }}'
         policy: "{{ lookup('template', 'console-policy.j2') | to_json }}"
       register: kms_policy_changed
```

##### EXPECTED RESULTS
Key successfully updated


##### ACTUAL RESULTS
Exception.  (There's actually a couple of places that need updating)


##### ADDITIONAL DETAILS
@willthames 

https://github.com/tremble/ansible/tree/aws_kms_keyid_only contains updated tests and a fix.  I'll submit a PR once we know what order everything's likely to get merged in.  Side effect of the change, aws_kms is substantially faster, as a result I had to more the iam_role creation in the test suite.
module.fail_json_aws(e, msg="Failed to create initial key")
    key = get_key_details(connection, module, result['KeyId'])
    alias = module.params['alias']
    if not alias.startswith('alias/'):
        alias = 'alias/' + alias
    try:
        connection.create_alias(AliasName=alias, TargetKeyId=key['key_id'])
    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
        module.fail_json_aws(e, msg="Failed to create alias")
    ensure_enabled_disabled(connection, module, key)
    for grant in module.params.get('grants'):
        grant_params = convert_grant_params(grant, key)
        try:
            connection.create_grant(**grant_params)
        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
            module.fail_json_aws(e, msg="Failed to add grant to key")
    
    result = get_key_details(connection, module, key['key_id'])
    module.exit_json(changed=True, **result)
def delete_key(connection, module, key):
    changed = False
    if key['key_state'] != 'PendingDeletion':
        try:
            connection.schedule_key_deletion(KeyId=key['key_id'])
            changed = True
        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
            module.fail_json_aws(e, msg="Failed to schedule key for deletion")
    result = get_key_details(connection, module, key['key_id'])
    module.exit_json(changed=changed, **result)
def get_arn_from_kms_alias(kms, aliasname):