##### 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.
policy_role_name:
    description:
    - (deprecated) Role to allow/deny access. One of C(policy_role_name) or C(policy_role_arn) are required.
    - Used for modifying the Key Policy rather than modifying a grant and only
      works on the default policy created through the AWS Console.
    - This option has been deprecated, and will be removed in 2.13. Use I(policy) instead.
    required: false
    aliases:
    - role_name
  policy_role_arn:
    description:
    - (deprecated) ARN of role to allow/deny access. One of C(policy_role_name) or C(policy_role_arn) are required.
    - Used for modifying the Key Policy rather than modifying a grant and only
      works on the default policy created through the AWS Console.
    - This option has been deprecated, and will be removed in 2.13. Use I(policy) instead.
    required: false
    aliases:
    - role_arn
  policy_grant_types:
    description:
    - (deprecated) List of grants to give to user/role. Likely "role,role grant" or "role,role grant,admin". Required when C(policy_mode=grant).
    - Used for modifying the Key Policy rather than modifying a grant and only
      works on the default policy created through the AWS Console.
    - This option has been deprecated, and will be removed in 2.13. Use I(policy) instead.
    required: false
    aliases:
    - grant_types
  policy_clean_invalid_entries:
    description:
    - (deprecated) If adding/removing a role and invalid grantees are found, remove them. These entries will cause an update to fail in all known cases.