Add more methods to IPowerManager.

Add the full list of transaction IDs from IPowerManager.aidl
to IPowerManager.h and make BpPowerManager support calling
goToSleep, reboot, shutdown, and crash. These are currently
needed by or likely to be needed by Brillo.

Bug: 22122485
Change-Id: I19abd3587c9d53b28ec150210e07f97517ee4ff4