[modify-image] Ensure qemu-img is installed

The role relies on qemu-image rpm, let's ensure
it's installed.

It used to be installed with tripleoclient before
[1], since the role relies on that rpm let's have
it as part of role.

Also use set -eo pipefail for convert image task
so that task fail if any part of the script fails.

[1] https://review.rdoproject.org/r/#/c/30690/

Closes-Bug: #1906486
Change-Id: I532e236caad86941db8a4cfcffa4be67c76502b5

roles/modify-image/tasks/manual.yml

@@ -13,6 +13,12 @@
   set_fact:
     mount_tempdir: "{{ mktemp_command.stdout }}"
 
+- name: Ensure qemu-img is installed
+  package:
+    name: qemu-img
+    state: present
+  become: true
+
 - when: not initramfs_image|bool
   block:
 
@@ -23,6 +29,7 @@
 
     - name: Convert image
       shell: >
+        set -eo pipefail;
         qemu-img convert -f qcow2 -O raw {{ image_to_modify_qcow }} {{ image_to_modify_raw }};
         rm -rf "{{ image_to_modify_qcow }}";