Fix discrepancy in policy name between policy_templates.json and enums.xml for policy id 403

Change-Id: Ie70563b27b64bc2c02b0a24ba79d1b35751c2177
Reviewed-on: https://chromium-review.googlesource.com/813918Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Commit-Queue: Kush Sinha <sinhak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522411}

tools/metrics/histograms/enums.xml

@@ -12057,7 +12057,7 @@ Called by update_net_error_codes.py.-->
   <int value="400" label="UnsafelyTreatInsecureOriginAsSecure"/>
   <int value="401" label="DefaultDownloadDirectory"/>
   <int value="402" label="SecurityKeyPermitAttestation"/>
-  <int value="403" label="NetworkHostname"/>
+  <int value="403" label="DeviceHostnameTemplate"/>
 </enum>
 
 <enum name="EnterprisePolicyInvalidations">