* opt log at release mode
* add MGE_OVERRIDE_LOG_LEVEL for runtime debug
//! env to config LogLevel
//!  DEBUG = 0, INFO = 1, WARN = 2, ERROR = 3, NO_LOG = 4
//! for example , export MGE_OVERRIDE_LOG_LEVEL=0, means set LogLevel to DEBUG

GitOrigin-RevId: 16cd674c56445b1f034359a2ac48beb7f86183a4