Add fieldtrial config for AndroidBlockExternalIntentsWithoutGesture

Bug: 927509
Change-Id: Icc150445dd72857d9d85fa2939e77bd7b1718c00
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2132399
Commit-Queue: Brian White <bcwhite@chromium.org>
Auto-Submit: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755934}

testing/variations/fieldtrial_testing_config.json

@@ -64,6 +64,21 @@
             ]
         }
     ],
+    "AndroidBlockExternalIntentsWithoutGesture": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled_20200323",
+                    "enable_features": [
+                        "IntentBlockExternalFormRedirectsNoGesture"
+                    ]
+                }
+            ]
+        }
+    ],
     "AndroidBlockIntentNonSafelistedHeaders": [
         {
             "platforms": [