Add ChromeHomeBottomNavLabels to fieldtrial_testing_config.json

Bug: 781340
Change-Id: Id9d18f4873ce0d47ed882ff9a6e00140f424b991
Reviewed-on: https://chromium-review.googlesource.com/782709
Commit-Queue: Troy Hildebrandt <thildebr@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519838}

testing/variations/fieldtrial_testing_config.json

@@ -779,6 +779,24 @@
             ]
         }
     ],
+    "ChromeHomeBottomNavLabels": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "ChromeHomeBottomNavLabels"
+                    ]
+                },
+                {
+                    "name": "Default"
+                }
+            ]
+        }
+    ],
     "ChromeHomeInactivitySheetExpansion": [
         {
             "platforms": [