Bug#965943: cloud.debian.org: ec2 buster arm64 don't come online in us-east-2

[Ross Vandegrift <rvandegrift@debian.org>]

Package: cloud.debian.org
Severity: normal
Usertags: aws

The buster arm64 images in us-east-2 don't seem to come online - ping and ssh
fail.  The ec2 status checks pass, but take unusually long to get there.  I
tried a1 and c6g instances.  There's nothing in the system log output, and no
screenshots on arm64.

I think it's the images since:
- amd64 in the same vpc, with the same security groups works correctly
- arm64 in us-west-2 & us-east-1 work correctly

Here's the images I tried:
  ami-0a5def50f0aa9c6a3
  ami-0a67a4b56b2021f1c
  ami-0b1808bb4e7ed5ff5

Ross