webos-image: Update layer pins for 2013-04-30

meta-webos as of 2013-04-30 15:28:53 -0700

28f9fc0 webos-image-devel: add bootchart package
20be7dd webos-image: nyx-modules=87, webos-shutdownscripts=36,v2.1.0
818cf67 webos-image: libpbnjson=9
f942086 webos-image: connman=v1.12, webos-connman-adapter=9

Open-webOS-DCO-1.0-Signed-off-by: Susan Montooth <susan.montooth@lge.com>