Added the precondition that the device should be charging to the
existing ones of the device not being used for awhile and the
battery level being high enough. Note that even if the device is
charging, we have to check the battery level since the user can
unplug it at any time.
bug:8688454
Change-Id: I709b1620571301743dc3504a6a625e2018951bfa
It is beneficial that there is a mechanism on the platform
to notify applications whether it is safe to perform somehow
expensive operations while the user is not using the device.
Thus, user experience will not be degraded. An example is
discarding of unused blocks on a mounted file system instead
of doing this on every write operation.
bug:8056794
Change-Id: I708bad9d3ce6c8f1d5a1c05c0abf46f81a3d464b