bootstrap: install network-scripts if EL8

network-scripts is required by the network service which is enabled
in tasks/main.yml.
Also run this block of tasks on EL8 only, where it's actually needed.

Change-Id: I2e43de001938bcdec96875ede0ef52d4742dc01c
Closes-bug: 1827277

roles/tripleo-bootstrap/tasks/main.yml

@@ -27,6 +27,14 @@
 # Note that we don't try to start the service since this is a one shot script
 # which can fail if someone tries to starts it a second time.
 # See https://bugzilla.redhat.com/show_bug.cgi?id=1701866 for context.
+- name: Deploy and enable network service
+  when: ansible_distribution_major_version == '8'
+  block:
+    - name: Deploy network-scripts required for deprecated network service
+      package:
+        name: network-scripts
+      become: true
+      ignore_errors: true
     - name: Ensure network service is enabled
       service:
         name: network