Modify screen-off behavior.

Set sched_upmigrate to 99 and sched_downmigrate to 95 when the screen is
off. This will make it harder to use the big cores when the screen is
off (saving power), but will still allow them to be used in case there
is actually a heavyweight task running.

bug 24130678

Change-Id: I8a8638f62e18cc8fac819d95c17e97ed4ff7e193
1 file changed