fedora-container: install dnf-plugins-core

Add dnf-plugins-core to the package-installs; this lets things like
"dnf copr" work automatically and is in-line with fedora-minimal base
packages.  While we're here, clean up some unneeded packages, and
remove the pkg-map that isn't relevant for Fedora builds.

Change-Id: Iad5a4717bcb55928377cc159b3360b0a70c5c5ac

diskimage_builder/elements/fedora-container/package-installs.yaml

@@ -1,4 +1,5 @@
 audit:
+dnf-plugins-core:
 dracut:
 dracut-config-generic:
 grubby:
@@ -11,10 +12,3 @@ linux-firmware:
     uninstall: true
 linux-firmware-whence:
     uninstall: true
-# NOTE(ianw) pkg-map restricts this to !rhel/centos 7; in 7
-# the "initscripts" package handles basic networking, in
-# 8+ it's the role of NetworkManager and dhcp-client.  This
-# mirrors the default packages installed in upstream cloud images
-# to facilitate a basic network.
-NetworkManager:
-dhcp-client:

diskimage_builder/elements/fedora-container/pkg-map

@@ -1,16 +1,8 @@
 {
-  "release": {
-      "centos": {
-          "7": {
-              "NetworkManager": "",
-              "dhcp-client": ""
-          }
+  "family": {
+      "redhat": {
+          "lsb_release": "redhat-lsb-core"
       }
-  },
-"family": {
-    "redhat": {
-      "lsb_release": "redhat-lsb-core"
-    }
   }
 }