Revert "Shutdown when capacity is 0% and no charging or when battery is dead"

This reverts commit fd04143a.

This break most automated tests because with this change, if the
device is fully charged, it will simply turn off the screen, regardless
if USB is connected to hsot PC or not; so for our tests, most of them
are always connected to host PC, and fully charged 99% of the time,
as soon as the screen turns off, the front-end test Activity will be
suspended.

Change-Id: I1e6590611af43812f1bac223dd31570d1d90cfc5