Update the doc text of unlisted

It should be "unlisted" instead of "private only".

Change-Id: I20922745236070fcdea0dac74c6d835029b59777
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2448685
Commit-Queue: Owen Min <zmin@chromium.org>
Commit-Queue: Julian Pastarmov <pastarmovj@chromium.org>
Auto-Submit: Owen Min <zmin@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813742}

components/policy/resources/policy_templates.json

@@ -23708,11 +23708,11 @@ The recommended way to configure policy on Windows is via GPO, although provisio
     },
     'doc_feature_unlisted': {
       'desc': '''The name of the feature that indicates whether a policy is set from cloud without any user interface.''',
-      'text': '''Private Only'''
+      'text': '''Unlisted'''
     },
     'doc_deprecated': {
       'desc': '''Text appended in parentheses to the policy name to indicate that it has been deprecated''',
-      'text': 'deprecated',
+      'text': 'Deprecated',
     },
     'doc_recommended': {
       'desc': '''Text appended in parentheses next to the policies top-level container to indicate that those policies are of the Recommended level''',