Create a field trial for CSD on Android.

Provide a field trial testing for client
side detection on Android.

Bug: 1108080
Change-Id: Idc40e3e9651f70eef1a6d651f01d14481cb2f529
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463968Reviewed-by: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Bettina Dea <bdea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816718}

testing/variations/fieldtrial_testing_config.json

@@ -1655,6 +1655,24 @@
             ]
         }
     ],
+    "ClientSideDetectionModelOnAndroid": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "EnabledWithModel55",
+                    "params": {
+                        "ModelNum": "55"
+                    },
+                    "enable_features": [
+                        "ClientSideDetectionModelOnAndroid"
+                    ]
+                }
+            ]
+        }
+    ],
     "CodeCacheDeletionWithoutFilter": [
         {
             "platforms": [