Put "Android CFI" below "chromium.memory" on main waterfall console.

I got this wrong in https://chromium-review.googlesource.com/c/chromium/src/+/1166429

TBR=dpranke@chromium.org

Bug: none
Change-Id: I4df8100ceece574176b1d45ff61e2709bdd4f2fd
Reviewed-on: https://chromium-review.googlesource.com/1167202Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581540}

infra/config/global/luci-milo.cfg

@@ -674,7 +674,7 @@ consoles {
   builders {
     name: "buildbot/chromium.memory/Android CFI"
     name: "buildbucket/luci.chromium.ci/Android CFI"
-    category: "android"
+    category: "chromium.memory|android"
     short_name: "cfi"
   }
   builders {