rhsm modules: cleanly fail when not run as root (#6211)

subscription-manager on RHEL installs a symlink in /usr/bin to
console-helper (part of usermode), which triggers an interactive prompt
for root credentials when run as user. It seems that console-helper
does not handle well non-interactive contexts (e.g. without a TTY for
input), and thus it will hang waiting for input when run as user in an
Ansible task.

Since subscription-manager requires root already anyway (and it will
fail when explicitly run as user), then apply the same logic locally on
all the modules that interact with it: redhat_subscription,
rhsm_release, and rhsm_repository.

tests/unit/plugins/modules/test_rhsm_release.py

@@ -30,9 +30,16 @@ class RhsmRepositoryReleaseModuleTestCase(ModuleTestCase):
         self.get_bin_path = self.mock_get_bin_path.start()
         self.get_bin_path.return_value = '/testbin/subscription-manager'
 
+        # subscription-manager needs to be run as root
+        self.mock_os_getuid = patch('ansible_collections.community.general.plugins.modules.rhsm_release.'
+                                    'os.getuid')
+        self.os_getuid = self.mock_os_getuid.start()
+        self.os_getuid.return_value = 0
+
     def tearDown(self):
         self.mock_run_command.stop()
         self.mock_get_bin_path.stop()
+        self.mock_os_getuid.stop()
         super(RhsmRepositoryReleaseModuleTestCase, self).tearDown()
 
     def module_main(self, exit_exc):