Is it possible to change the initial position of the /map frame in order to match the actual starting robot position in gazebo (and the local costmap)?

edit

My question is, is there an accurate after spawning the husky at a different location in the world scene and initializing the amcl.launch to calibrate the /map frame in order to match the actual location in the world scene?

I'm not sure to understand what you mean here.

it is necessary to spawn the robot at the same location where the mapping process has begun.

You are not forced to do so, but if you do know where you spawn your robot you can tell it to AMCL using the topic /initialpose that the AMCL node is subscribing to (you can set it from the launch file or publish it with rostopic or Rviz). You will find an accurate localization faster if you specify a good estimation of the initial pose, but if you don't it's still the function of the ACML to find where your robot is so it might just take more time to have the particule filter to converge. What is happening when you set the intialpose is that you initialize the particle filter around this position.