Set linux autoroller as bringup to reopen the tree. (#110739)

The build is failing to decrypt the key after it was moved to a
different GCP project. Disabling temporarily to reopen the tree while
the key is regenerated.

.ci.yaml

@@ -155,6 +155,7 @@ targets:
 
   - name: Linux packages_autoroller
     presubmit: false
+    bringup: true
     recipe: pub_autoroller/pub_autoroller
     timeout: 30
     enabled_branches: