device_config_flags_health_check_prop is used for enabling/disabling
program flags_health_check which is executed during device booting.
"1" means enabling health check actions in flags_health_check, other
values mean flags_health_check will not perform any action.

Test: build succeeded & manual test
Change-Id: I93739dc5d155e057d72d08fd13097eb63c1193b5