Cache is not used on the device using AB update. In that case, init just
waits
for timeout 5s.
[ 18.904216] init: Command 'mount_all fstab.${ro.hardware}' action=fs
(/init.taimen.rc:33) returned 1 took 767.808ms.
[ 23.911072] init: Command 'wait /dev/block/bootdevice/by-name/cache'
action=fs (/init.taimen.rc:40) returned -1 took 5006.36ms.
Test: Build and tested on a device
Change-Id: Iaee76961c98b7b7873e532a7003d560ebf6c4752