Update the default root volume size to 45 GB

[hgreebe]

Signed-off-by: Hanwen [email protected]
(cherry picked from commit 98c689e)

References

• Original PR: Update the default root volume size to 45 GB #2908
• Corresponding CLI PR: Update the default root volume size to 45 GB aws-parallelcluster#6712

Checklist

• Make sure you are pointing to the right branch.
• If you're creating a patch for a branch other than develop add the branch name as prefix in the PR title (e.g. [release-3.6]).
• Check all commits' messages are clear, describing what and why vs how.
• Make sure to have added unit tests or integration tests to cover the new/modified code.
• Check if documentation is impacted by this change.

Please review the guidelines for contributing and Pull Request Instructions.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.