### 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
```

netbsd_facts = {}
        platform_release = platform.release()
        netbsd_facts['distribution_release'] = platform_release
        rc, out, dummy = self.module.run_command("/sbin/sysctl -n kern.version")
        match = re.match(r'NetBSD\s(\d+)\.(\d+)\s\((GENERIC)\).*', out)
        if match:
            netbsd_facts['distribution_major_version'] = match.group(1)
            netbsd_facts['distribution_version'] = '%s.%s' % match.groups()[:2]
        else:
            netbsd_facts['distribution_major_version'] = platform_release.split('.')[0]
            netbsd_facts['distribution_version'] = platform_release
        return netbsd_facts
    def get_distribution_SMGL(self):
        smgl_facts = {}
        smgl_facts['distribution'] = 'Source Mage GNU/Linux'
        return smgl_facts
    def get_distribution_SunOS(self):
        sunos_facts = {}
        data = get_file_content('/etc/release').splitlines()[0]
        if 'Solaris' in data:
            
            uname_r = get_uname(self.module, flags=['-r'])
            ora_prefix = ''
            if 'Oracle Solaris' in data:
                data = data.replace('Oracle ', '')
                ora_prefix = 'Oracle '