### Summary

Ansible no longer returns distribution facts for my Amazon Linux 2 instances after #73767.

### Issue Type

Bug Report

### Component Name

setup

### Ansible Version

```console (paste below)
$ ansible --version
ansible [core 2.11.0b2.post0]  (detached HEAD 30c465c1a9) last updated 2021/03/17 18:53:46 (GMT -400)
  config file = /home/ec2-user/ansible-aws-coll/ansible/ansible.cfg
  configured module search path = ['/home/ec2-user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/ec2-user/tmp/ansible/lib/ansible
  ansible collection location = /home/ec2-user/ansible-aws-coll/ansible/collections
  executable location = /home/ec2-user/tmp/ansible/bin/ansible
  python version = 3.8.5 (default, Feb 18 2021, 01:24:20) [GCC 7.3.1 20180712 (Red Hat 7.3.1-12)]
  jinja version = 2.11.3
  libyaml = True
```


### Configuration

```console (paste below)
$ ansible-config dump --only-changed
DEVEL_WARNING(env: ANSIBLE_DEVEL_WARNING) = False
```


### OS / Environment

Amazon Linux 2

### Steps to Reproduce

```
ansible localhost -m setup | grep distribution
```


### Expected Results

With 78d3810fdf:
```
[WARNING]: No inventory was parsed, only implicit localhost is available
        "ansible_distribution": "Amazon",
        "ansible_distribution_file_parsed": true,
        "ansible_distribution_file_path": "/etc/system-release",
        "ansible_distribution_file_variety": "Amazon",
        "ansible_distribution_major_version": "2",
        "ansible_distribution_release": "NA",
        "ansible_distribution_version": "2",
```

### Actual Results

```console (paste below)
[WARNING]: No inventory was parsed, only implicit localhost is available
```

OS_FAMILY_MAP = {'RedHat': ['RedHat', 'Fedora', 'CentOS', 'Scientific', 'SLC',
                                'Ascendos', 'CloudLinux', 'PSBM', 'OracleLinux', 'OVS',
                                'OEL', 'Amazon', 'Virtuozzo', 'XenServer', 'Alibaba',
                                'EulerOS', 'openEuler', 'AlmaLinux'],
                     'Debian': ['Debian', 'Ubuntu', 'Raspbian', 'Neon', 'KDE neon',
                                'Linux Mint', 'SteamOS', 'Devuan', 'Kali', 'Cumulus Linux',
                                'Pop!_OS', 'Parrot', 'Pardus GNU/Linux'],
                     'Suse': ['SuSE', 'SLES', 'SLED', 'openSUSE', 'openSUSE Tumbleweed',
                              'SLES_SAP', 'SUSE_LINUX', 'openSUSE Leap'],
                     'Archlinux': ['Archlinux', 'Antergos', 'Manjaro'],
                     'Mandrake': ['Mandrake', 'Mandriva'],
                     'Solaris': ['Solaris', 'Nexenta', 'OmniOS', 'OpenIndiana', 'SmartOS'],
                     'Slackware': ['Slackware'],
                     'Altlinux': ['Altlinux'],
                     'SGML': ['SGML'],
                     'Gentoo': ['Gentoo', 'Funtoo'],
                     'Alpine': ['Alpine'],
                     'AIX': ['AIX'],
                     'HP-UX': ['HPUX'],
                     'Darwin': ['MacOSX'],
                     'FreeBSD': ['FreeBSD', 'TrueOS'],
                     'ClearLinux': ['Clear Linux OS', 'Clear Linux Mix'],
                     'DragonFly': ['DragonflyBSD', 'DragonFlyBSD', 'Gentoo/DragonflyBSD', 'Gentoo/DragonFlyBSD'],
                     'NetBSD': ['NetBSD'], }
    OS_FAMILY = {}
    for family, names in OS_FAMILY_MAP.items():
        for name in names:
            OS_FAMILY[name] = family
    def __init__(self, module):