Promote android_n5x_swarming_rel to non-experimental.

BUG=589168

Review-Url: https://codereview.chromium.org/2318813002
Cr-Commit-Position: refs/heads/master@{#417416}

infra/config/cq.cfg

@@ -32,10 +32,7 @@ verifiers {
       builders { name: "android_arm64_dbg_recipe" }
       builders { name: "android_clang_dbg_recipe" }
       builders { name: "android_compile_dbg" }
-      builders {
-        name: "android_n5x_swarming_rel"
-        experiment_percentage: 100
-      }
+      builders { name: "android_n5x_swarming_rel" }
       builders { name: "cast_shell_android" }
       builders {
         name: "android_cronet"