Add finch fieldtrial testing config for network time queries

testing/variations/fieldtrial_testing_config_ios.json

 {
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillProfileOrderByFrecency": [
         {
             "group_name": "EnabledLimitTo3",
             "params": {
@@ skipping 13 matching lines @@
         }
     ],
     "DataCompressionProxyDevRollout": [
         {
             "group_name": "Control"
         },
         {
             "group_name": "Enabled"
         }
     ],
+    "NetworkTimeQueries": [
+        {
+            "enable_features": [
+                "NetworkTimeServiceQuerying"
+            ],
+            "group_name": "NetworkTimeQueriesEnabled"
+        }
+    ],
     "PageRevisitInstrumentation": [
         {
             "group_name": "Enabled"
         }
     ],
     "PasswordBranding": [
         {
             "group_name": "SmartLockBrandingSavePromptOnly"
         }
     ],
@@ skipping 22 matching lines @@
     ],
     "VarationsServiceControl": [
         {
             "group_name": "Interval_30min",
             "params": {
                 "fetch_period_min": "30"
             }
         }
     ]
 }