staging: android: lowmemorykiller: Reduce debug_level to 1

Under certain circumstances, such as after the lowmemorykiller
has recently killed an application, the logs can get flooded
with "select to kill" messages.

Change-Id: I7ae1de47c77d929e04b99be3432577d4f5fd1b2d
Signed-off-by: Liam Mark <lmark@codeaurora.org>