Temporarily remove ASAN builders from garden-o-matic.

The ASAN builders have the largest failures file and loading
this file makes garden-o-matic unusable.

We should have a better fetch/update startegy, but for now
disable showing ASAN builders in garden-o-matic.

TBR=dpranke
BUG=336968

Review URL: https://codereview.chromium.org/148333010

git-svn-id: svn://svn.chromium.org/blink/trunk@165958 bbb929c8-8fbe-4397-9dbb-9b2b20218538