[FYI] Tools AMI Baking: apt cache update failed

Context:
We have identified several AMI baking job failed with apt cache update failed error. Root cause is still unknown but so far this only happen with AMI baking using Ubuntu 16 Golden AMI. The mitigation is to move to Ubuntu 20.

Solution:
If you encounter this error, please follow this guide
Tools AMI Baking: Error apt cache update failed