Relax background restriction to 16.67%

To avoid background starvation and PI, especially for those low prio 130
threads within system_server, allocate more cpu shares for background
sched group.

Test: boot and torture a loaded device.
Bug: 201428466
Signed-off-by: Wei Wang <wvw@google.com>
Change-Id: Ia85814294f9534fd83388a72c574c04f631a185f
1 file changed