extractAttitude in Utils

[blueRaining]

in Utils.ts, MapViewUtils extractAttitude i find extractAttitude

yaw = Math.atan2(-space.y.x, space.x.x);
i find if yaw = Math.atan2(space.y.x, space.x.x); the yaw equal when mapview initialization，
but when yaw = Math.atan2(-space.y.x, space.x.x);,the yaw not equal when mapview initialization,it equal negative heading