Update Field Trails with AppLauncherRefresh expirement

Create a field trail entry before experimenting with 50% Beta

Bug: 850760
Change-Id: Ie2796f43a0443ac8bc8a77ac2db8057b32d989d2
Reviewed-on: https://chromium-review.googlesource.com/1234356Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Mohammad Refaat <mrefaat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592927}

testing/variations/fieldtrial_testing_config.json

@@ -428,6 +428,21 @@
             ]
         }
     ],
+    "AppLauncherRefresh": [
+        {
+            "platforms": [
+                "ios"
+            ],
+            "experiments": [
+                {
+                    "name": "AppLauncherRefresh",
+                    "enable_features": [
+                        "AppLauncherRefresh"
+                    ]
+                }
+            ]
+        }
+    ],
     "AppleScriptExecuteJavaScript": [
         {
             "platforms": [