Increase -j for android-binary-size builder

This is for more than 30 mins compile steps like below builds.

2254s https://ci.chromium.org/b/8939878092028048128
2251s https://ci.chromium.org/b/8939877984227459216
2131s https://ci.chromium.org/b/8939881577503817376
1987s https://ci.chromium.org/b/8939876145878190960

Bug: 804251
Change-Id: I7d98659f30ab009b89b0b95f86079e296dc408fc
Reviewed-on: https://chromium-review.googlesource.com/1152719Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578958}

infra/config/global/cr-buildbucket.cfg

@@ -2358,6 +2358,7 @@ buckets {
     builders {
       name: "android-binary-size"
       mixins: "android-try"
+      mixins: "goma-j150"
       dimensions: "os:Ubuntu-14.04"
       recipe {
         name: "binary_size_trybot"