Add android-marshmallow-arm64-rel to try builders consoles

Bug: 859445
Change-Id: I28c1176c89efd35ba959a0a710f51d759e155cfa
Reviewed-on: https://chromium-review.googlesource.com/1123972
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572132}

infra/config/global/luci-milo.cfg

@@ -4722,6 +4722,9 @@ consoles {
   builders {
     name: "buildbucket/luci.chromium.try/android-kitkat-arm-rel"
   }
+  builders {
+    name: "buildbucket/luci.chromium.try/android-marshmallow-arm64-rel"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/android_arm64_dbg_recipe"
   }