Change PrivacyScreen Policies version to M83

Migrating the supported release branch for PrivacyScreenEnabled and
DeviceLoginScreenPrivacyScreenEnabled into M83, instead of referencing
to the defunct M82 release.

BYPASS_POLICY_COMPATIBILITY_CHECK=tested on M83

Change-Id: I56c1cb918396f3c76030215458be56ebef1a8029
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2148842Reviewed-by: Oleh Lamzin <lamzin@google.com>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Commit-Queue: Gil Dekel <gildekel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758957}

components/policy/resources/policy_templates.json

@@ -20246,7 +20246,7 @@
       'device_only': True,
       'type': 'main',
       'schema': { 'type': 'boolean' },
-      'supported_on': ['chrome_os:82-'],
+      'supported_on': ['chrome_os:83-'],
       'features': {
         'can_be_mandatory' : True,
         'can_be_recommended': False,
@@ -20272,7 +20272,7 @@ If this policy is left unset, the privacy screen is disabled initially, but rema
       'owners': ['lamzin@google.com', 'gildekel@chromium.org'],
       'type': 'main',
       'schema': { 'type': 'boolean' },
-      'supported_on': ['chrome_os:82-'],
+      'supported_on': ['chrome_os:83-'],
       'features': {
         'can_be_mandatory' : True,
         'can_be_recommended': False,