lowmemorykiller: change default debug_level to 1 [Christopher83]
The select to kill messages are not very useful when not debugging the lowmemorykiller itself.
After the change to check TIF_MEMDIE instead of using a task notifier this message can also get very noisy.

Change-Id: Ice171c25801d6faa454b885a23b24b002423b754
Signed-off-by: Arve Hjønnevåg <arve@android.com>