Add additional OS installer images

- Debian 11, Ubuntu 20.04, and OpenBSD 7.0 images
  - Menu is too long, so added pxeboot_boot_images list to determine
    which images to download/include in menu
- Update versions and checksums downloaded for existing images, and use
  version specific paths where applicable.
- Update boot parameters to better support EFI booting
- Update galaxy metadata

Change-Id: Iab6d4385489458ff0e4491c4b1de544b442c2622
diff --git a/tasks/ubuntu2004.yml b/tasks/ubuntu2004.yml
new file mode 100644
index 0000000..4d60af9
--- /dev/null
+++ b/tasks/ubuntu2004.yml
@@ -0,0 +1,26 @@
+---
+# pxeboot tasks/ubuntu2004.yml
+#
+# SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+# SPDX-License-Identifier: Apache-2.0
+
+- name: Create ubuntu2004 dir in webroot
+  file:
+    state: directory
+    path: "{{ pxeboot_web_root }}/ubuntu2004"
+    owner: "{{ pxeboot_username }}"
+    group: "{{ pxeboot_groupname }}"
+    mode: "0755"
+
+- name: Download ubuntu2004 files
+  get_url:
+    url: "{{ pxeboot_ubuntu2004_base_url }}/{{ pxeboot_ubuntu2004_version }}/{{ item['name'] }}"
+    dest: "{{ pxeboot_web_root }}/ubuntu2004/{{ item['name'] }}"
+    checksum: "{{ item['checksum'] }}"
+    owner: "{{ pxeboot_username }}"
+    group: "{{ pxeboot_groupname }}"
+    mode: "0644"
+  with_items: "{{ pxeboot_ubuntu2004_files }}"
+
+# NOTE: Ubuntu 20.04 switched away from using preseed to an autoinstall method
+# https://ubuntu.com/server/docs/install/autoinstall