Adding improved geolanguage field trial testing config.

Bug: 850947
Change-Id: I4745016ce722df5d2664215b16a5ab2a2ab69150
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1505999
Commit-Queue: Alexandre Frechette <frechette@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638175}

testing/variations/fieldtrial_testing_config.json

@@ -2249,6 +2249,21 @@
             ]
         }
     ],
+    "ImprovedGeolanguageReplacement": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "ImprovedGeoLanguageData"
+                    ]
+                }
+            ]
+        }
+    ],
     "ImprovedRecoveryComponent": [
         {
             "platforms": [