Fix DeviceChromeVariations description

Bug: b/151692396
Change-Id: I3c2830bae15a07dd853ed4ae7ec9e87cad6e3f53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2119855Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Commit-Queue: Amr Aboelkher <amraboelkher@google.com>
Cr-Commit-Position: refs/heads/master@{#753262}

components/policy/resources/policy_templates.json

@@ -11737,7 +11737,7 @@
       },
       'example_value': 1,
       'id': 674,
-      'caption': '''Determine the availability of variations on ChromeOS''',
+      'caption': '''Determine the availability of variations on <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph>''',
       'tags': [],
       'desc': '''Configuring this policy allows to specify which variations are allowed to be applied on an enterprise-managed <ph name="PRODUCT_OS_NAME">$2<ex>Google Chrome OS</ex></ph> device.