ANDROID: sched: add restrict vendor hook to modify task placement policy in EAS

For modifying task placement policy, we add the hook on the top of
select_task_rq_fair(). It allows us to modify wakeup/fork/exec balance
paths.

Bug: 158263250
Signed-off-by: Yun Hsiang <yun.hsiang@mediatek.com>
Change-Id: I80ff870453472e183ab2aae7381bff91e49ae296