build_inf_prepare_jenkins: remove installation of docker

build_inf_prepare_jenkins: remove installation of docker

docker-ce is already installed on CI vm:

08:45:40 Transaction check error:
08:45:40   file /usr/bin/docker from install of docker-common-2:1.13.1-209.git7d71120.el7.centos.x86_64 conflicts with file from package docker-ce-cli-1:20.10.8-3.el7.x86_64
08:45:40   file /usr/bin/dockerd from install of docker-common-2:1.13.1-209.git7d71120.el7.centos.x86_64 conflicts with file from package docker-ce-3:20.10.8-3.el7.x86_64

Issue-ID: INF-274

Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Change-Id: Icf41b9fc4fd234720298f70ba1e4d600a6c78576