Revert "hammerhead: disable retention mode"
Revert "hammerhead: disable retention mode"

This reverts commit 5ec28ab68175d174438dc58c94a204497334fcca.

Change-Id: I75a138187caa5097e9911838bb41a0abd13de8fc

maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead