Docker-in-docker pod doesn't work in some k8s environments because it
always assumes MTU=1500, even when k8s container network's MTU is
smaller than that. This causes downloads to fail intermittently in
containers that run within the internal docker.
Solution: allow option to override MTU in docker helm chart & the stx
tool.
Also: remove explicit reference to dockerd entry point script from the
helm chart because its name may change in future docker image versions.
TESTS
=======================================
Make sure "--mtu" is passed or omitted when starting docker daemon
depending on whether STX_CONTAINER_MTU is defined.
Story: 2010055
Task: 45691
Signed-off-by: Davlet Panech <davlet.panech@windriver.com>
Change-Id: Iaee08ee8d568d28fe9e8cdc11f0308aa9ff32d42
b11b136df0