{feature}-installer.zip not copied to docker image

{feature}-installer.zip not copied to docker image

The "generate-sources" phase assigned to
docker-maven-plugin occurs much earlier
than phase of for building and staging
*-installer zip files. This leads to
image not having any of these zip, thus
ODL inside appc containers fails to load
appc feature repos.

The right Maven lifecycle phase for building
docker should be "package" as this creates
docker-build.tar.

Also, note that file permissions change added
to Dockerfile is redundant now that phase is
corrected.

Change-Id: I5565771de5de0593de1aad25f60e4001972712c2
Signed-off-by: Rashmi Pujar <rashmi.pujar@bell.ca>