Use custom dind image based on alpine
Use custom dind image based on alpine

This allows us to continue supporting armv7 even though
the official dind images stopped at docker v19.

Change-type: minor
Signed-off-by: Kyle Harding <3c25b01657254677d3e1a8fd1f0742c5d489bd39@balena.io>

resin-io/resin-preload-image-script,resin-io/resin-preload-image-script