Values:
POWER_STATE_UNSPECIFIED (0):
Power state is unknown.
PENDING (1):
The machine is preparing to enter the ACTIVE
state. An instance may enter the PENDING state
when it launches for the first time, or when it
is started after being in the SUSPENDED state.
ACTIVE (2):
The machine is active.
SUSPENDING (3):
The machine is being turned off.
SUSPENDED (4):
The machine is off.
DELETING (5):
The machine is being deleted from the hosting
platform.
DELETED (6):
The machine is deleted from the hosting
platform.
