cloud-init: Increase /var/lib/cloud max size

GCE supports metadata values up to 256K in size. This means that
user-data cloud-configs are technically allowed by GCE to be up to 256K
in size. 1MB isn't large enough to contain all cloud-init data when
using such a large cloud-config; roughly 1.5MB is needed. Let's increase
/var/lib/cloud size to 2MB to allow for large cloud-configs.

The tmpfs size here does not increase passive memory usage, so users
will not pay for this additional memory unless they use a large
cloud-config.

BUG=b/232463064
TEST=presubmit, boot on GCE with large cloud-config
RELEASE_NOTE=Fixed an issue that prevented large cloud-configs (~256KB)
from working properly.

Change-Id: I8741265ffa69ef1b20cdc8c1e7ed065ef53e0a2c
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/32761
Reviewed-by: Dexter Rivera <riverade@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
2 files changed