Adding my original rationale for the record, I overrode IsDeprecatedPolicySupported and IsFuturePolicySupported as I thought it made sense to expose them until they are deleted or for testing new policies using the policy management tools.
Makes sense to remove them if confusing.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0d9428bb6b7d6a77e1d68f26d5dad81b224148d5

commit 0d9428bb6b7d6a77e1d68f26d5dad81b224148d5
Author: aberent <aberent@chromium.org>
Date: Tue Nov 29 10:31:10 2016

[Android app restrictions] Hide unused and improve descriptions.

Remove future and deprecated policies from app_restrictions.xml and
restriction_values.xml, hence making them invisible to Android policy
managers. Also include all lines of multiline descriptions of policies.

BUG= 616800 
BUG= 616801 

Review-Url: https://codereview.chromium.org/2529383003
Cr-Commit-Position: refs/heads/master@{#434949}

[modify] https://crrev.com/0d9428bb6b7d6a77e1d68f26d5dad81b224148d5/components/policy/tools/generate_policy_source.py
[modify] https://crrev.com/0d9428bb6b7d6a77e1d68f26d5dad81b224148d5/tools/grit/grit/format/policy_templates/writers/android_policy_writer.py
[modify] https://crrev.com/0d9428bb6b7d6a77e1d68f26d5dad81b224148d5/tools/grit/grit/format/policy_templates/writers/android_policy_writer_unittest.py