revert Revert hammerhead: switch back to ondemand till slim govenour is back

want to tweak it before we use it on lp again.

Change-Id: I8960ec7a7e25aea5954669df19719d65b031ab2b (reverted from commit 2e67ed592439d720881a64f7cf7699513f8702bb) (reverted from commit b2bbd3beb568999fb6cdacb6cca178169056df7e)