Mark NetworkPredictionWifiOnly policy setting as deprecated

components/policy/resources/policy_templates.json

 {
 # policy_templates.json - Metafile for policy templates
 #
 # The content of this file is evaluated as a Python expression.
 #
 # This file is used as input to generate the following policy templates:
 # ADM, ADMX+ADML, MCX/plist and html documentation.
 #
 # Policy templates are user interface definitions or documents about the
 # policies that can be used to configure Chrome. Each policy is a name-value
@@ skipping 402 matching lines @@
       },
       'items': [
         {
           'name': 'NetworkPredictionAlways',
           'value': 0,
           'caption': '''Predict network actions on any network connection''',
         },
         {
           'name': 'NetworkPredictionWifiOnly',
           'value': 1,
-          'caption': '''Predict network actions on any network that is not
-          cellular''',
+          'caption': '''Predict network actions on any network that is not cellular.
+          (Deprecated in 50, removed in 52. After 52, if value 1 is set, it will be treated as 0 - predict network actions on any network connection.)''',
         },
         {
           'name': 'NetworkPredictionNever',
           'value': 2,
           'caption': '''Do not predict network actions on any network connection''',
         },
       ],
       'supported_on': ['chrome.*:38-', 'chrome_os:38-', 'android:38-'],
       'features': {
         'can_be_recommended': True,
@@ skipping 8064 matching lines @@
       'desc': '''Text appended in parentheses next to the policies top-level container to indicate that those policies are of the Recommended level''',
       'text': 'Default Settings (users can override)',
     },
     'doc_complex_policies_on_windows': {
       'desc': '''Text pointing the user to a help article for complex policies on Windows''',
       'text': '''encoded as a JSON string, for details see <ph name="COMPLEX_POLICIES_URL">https://www.chromium.org/administrators/complex-policies-on-windows<ex>https://www.chromium.org/administrators/complex-policies-on-windows</ex></ph>''',
     },
   },
   'placeholders': [],
 }