### Summary

Based on feedback from a mastodon ansible user:

The first example of https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_key_module.html#examples (the apt_key replacement) shows how a pgp key is downloaded and declared as trusted for a repository, but there is no validation of the key going on. Maybe the get_url task could include the checksum argument, to show that (and how) the key should be validated against a known good. Further down there is also an example of apt_key downloading a key without the id argument specified.

### Issue Type

Documentation Report

### Component Name

apt_key

### Ansible Version

```console
$ ansible --version
2.15
```


### Configuration

```console
# if using a version older than ansible-core 2.12 you should omit the '-t all'
$ ansible-config dump --only-changed -t all
none
```


### OS / Environment

none

### Additional Information

The examples all use https URLs, so they do not expose you to just arbitrary MITM; but many projects use untrusted public mirrors to distribute packages and public keys, and instead post the fingerprint of the public key on the non-mirrored first-party website. You are then supposed to verify the downloaded key against that fingerprint (unfortunately a manual action since they post a PGP fingerprint and not a checksum), in order to protect against rogue mirror operators (AFAIK).

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
RETURN = '''
after:
    description: List of apt key ids or fingerprints after any modification
    returned: on change
    type: list
    sample: ["D8576A8BA88D21E9", "3B4FE6ACC0B21F32", "D94AA3F0EFE21092", "871920D1991BC93C"]
before:
    description: List of apt key ids or fingprints before any modifications
    returned: always
    type: list
    sample: ["3B4FE6ACC0B21F32", "D94AA3F0EFE21092", "871920D1991BC93C"]
fp:
    description: Fingerprint of the key to import
    returned: always
    type: str
    sample: "D8576A8BA88D21E9"
id:
    description: key id from source
    returned: always
    type: str
    sample: "36A1D7869245C8950F966E92D8576A8BA88D21E9"
key_id:
    description: calculated key id, it should be same as 'id', but can be different
    returned: always
    type: str
    sample: "36A1D7869245C8950F966E92D8576A8BA88D21E9"
short_id:
    description: calculated short key id
    returned: always
    type: str