Read LPNH touch slop percentage and timeout ms from DeviceConfig.

Make CUSTOM_LPNH_THRESHOLDS as a ReleaseFlag so this can be enabled from
server for experiments since touch slop percentage and timeout are
applied only when CUSTOM_LPNH_THRESHOLDS is enabled.

Add FeatureFlags for LPNH slop multiplier is "lpnh_slop_percentage" and LPNH timeout is "lpnh_timeout_ms"

Bug: 301680992
Flag: Legacy CUSTOM_LPNH_THRESHOLDS DISABLED
Test: Manual

Change-Id: Ifd066b8cb8521dceb7aa12d9e46f5b7cfce1ec7f