Add a missing zero to MaxInvalidationFetchDelay max value

Change-Id: If69f63281c1117aacc79cae163bb1ee609b255cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2522238Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Chris Sharp <csharp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824998}

components/policy/resources/policy_templates.json

@@ -7126,7 +7126,7 @@
       'name': 'MaxInvalidationFetchDelay',
       'owners': ['stepco@chromium.org', 'poromov@chromium.org'],
       'type': 'int',
-      'schema': { 'type': 'integer', 'minimum': 1000, 'maximum': 30000 },
+      'schema': { 'type': 'integer', 'minimum': 1000, 'maximum': 300000 },
       'supported_on': ['chrome.*:30-', 'chrome_os:30-'],
       'features': {
         'dynamic_refresh': True,