lowmemorykiller: Overwrite LMK parameters for low-tier devices

LMK parameters calculated by default algorithm were not optimal for
low-tier devices. Values mentioned here were well tested and
evaluated w.r.t memory and performance for such setups.

Change-Id: I40ed92d204aae6e758028ea1e9bd4ec7226dbe2b

lowmemorykiller: fine-tune LMK parameters for low-tier devices

LMK parameters for low-tier devices are fine-tuned for better
concurrency. Values mentioned here were well tested and
evaluated w.r.t memory and performance for such setups.

Change-Id: I0d547f1ec84863bbaedb68d9aba1ff7aef057e42