Remove obsolete SpeculativeResourcePrefetching trial from fieldtrial_testing_config_android.json.

testing/variations/fieldtrial_testing_config_android.json

 {
     "AllBookmarks": [
         {
             "disable_features": [
                 "AllBookmarks"
             ],
             "group_name": "Disabled"
         }
     ],
     "AndroidSessionNotifications": [
@@ skipping 430 matching lines @@
     "SchedulerExpensiveTaskBlocking": [
         {
             "group_name": "Enabled"
         }
     ],
     "SdchPersistence": [
         {
             "group_name": "Enabled"
         }
     ],
-    "SpeculativeResourcePrefetching": [
-        {
-            "group_name": "v=1a:Prefetching=Enabled:Predictor=Url"
-        },
-        {
-            "group_name": "v=1b:Prefetching=Enabled:Predictor=Url:Confidence=High"
-        },
-        {
-            "group_name": "v=1c:Prefetching=Enabled:Predictor=Url:Confidence=Low"
-        },
-        {
-            "group_name": "v=1d:Prefetching=Enabled:Predictor=Host"
-        },
-        {
-            "group_name": "v=1e:Prefetching=Enabled:Predictor=Host:Confidence=High"
-        },
-        {
-            "group_name": "v=1f:Prefetching=Enabled:Predictor=Host:Confidence=Low"
-        },
-        {
-            "group_name": "v=1:Prefetching=Learning"
-        }
-    ],
     "StrictSecureCookies": [
         {
             "group_name": "Enabled"
         }
     ],
     "SyncHttpContentCompression": [
         {
             "group_name": "Enabled"
         },
         {
@@ skipping 121 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }