Move selinux packages to redhat-common

Change I008f8bbc9c8414ce948c601e3907e27764e15a52 has shown that we
build redhat images without the "semange" tool available, which comes
from the policycoreutils-python package (see also
I3f9e2c322d042a5dddba33451c0fc21a4d32a88a).

I403e7806ae10d5dd96d0727832f4da20e34b94c7 added some of the selinux
libraries to yum-minimal for ansible support, but not to others.

Given both these changes, it seems that selinux[-targeted],
libselinux[-python] and policycoreutils[-python] can reasonably
considered part of all base images.  Move the selinux related packages
into redhat-common.

This also adds it explicitly to install_test_deps.sh.  It was actually
being dragged in by the docker install, but is a required component
for building (should be in bindep, but not there with that yet).

Change-Id: Idd4ae71ee6deee84604823b6b5dc4a845f316e01
Related-Bug: #1707788

diskimage_builder/elements/redhat-common/package-installs.yaml

@@ -6,3 +6,10 @@ traceroute:
 which:
 gettext:
     phase: pre-install.d
+
+# selinux-targeted policy and related tools
+selinux-policy:
+selinux-policy-targeted:
+libselinux-python:
+policycoreutils:
+policycoreutils-python:

diskimage_builder/elements/yum-minimal/package-installs.yaml

@@ -6,7 +6,4 @@ kernel:
 initscripts:
 man-pages:
 lsb_release:
-selinux-policy:
-selinux-policy-targeted:
-libselinux-python:
 redhat-rpm-config:

tests/install_test_deps.sh

@@ -23,7 +23,8 @@ sudo apt-get install -y --force-yes \
         docker \
         kpartx \
         util-linux \
-        qemu-img || \
+        qemu-img \
+        policycoreutils-python || \
     sudo zypper -n install \
         bzip2 \
         debootstrap \