Set lmk stall_limit_critical threshold

To prevent APC watchdog under heavy memory pressure,
set stall_limit_critical to 40.

Bug: 205182133
Test: Run ACT under a heavy memory pressure
Signed-off-by: Martin Liu <liumartin@google.com>
Change-Id: Iaac006d1b1f2fff8a47875e792f6d2179bae80a9
Merged-In: Iaac006d1b1f2fff8a47875e792f6d2179bae80a9