Enable android-binary-size trybot on CQ as a 10% experiment

Bug: 702625
Change-Id: I68ff5c0b3e81da58ca85cd2a6b26ebe7ec80456e
Reviewed-on: https://chromium-review.googlesource.com/1112351Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569714}

infra/config/branch/cq.cfg

@@ -32,6 +32,11 @@ verifiers {
     buckets {
       name: "luci.chromium.try"
       builders { name: "android_arm64_dbg_recipe" }
+      # https://crbug.com/702625
+      builders {
+        name: "android-binary-size"
+        experiment_percentage: 10
+      }
       builders { name: "android_clang_dbg_recipe" }
       builders { name: "android_compile_dbg" }
       builders { name: "android_cronet" }