Add retries to get_url and uri tasks

These tasks occasionally fail in CI, causing jobs to fail.

Change-Id: I89041a641d8cb66c7848fa9ae9264a51aa1e38c8
(cherry picked from commit 2951f26)

ansible/roles/apt/tasks/keys.yml

@@ -17,3 +17,7 @@
     mode: 0644
   loop: "{{ apt_keys }}"
   become: true
+  register: result
+  until: result is successful
+  retries: 3
+  delay: 5

ansible/roles/dell-switch-bmp/tasks/main.yml

@@ -20,3 +20,7 @@
   notify:
     - Copy Dell switch BMP images
   become: True
+  register: result
+  until: result is successful
+  retries: 3
+  delay: 5

ansible/roles/image-download/tasks/main.yml

@@ -12,6 +12,9 @@
             url: "{{ image_download_checksum_url }}"
             return_content: true
           register: expected_checksum
+          until: expected_checksum is successful
+          retries: 3
+          delay: 5
       when:
         - image_download_checksum_url is not none
         - image_download_checksum_url != ""
@@ -29,6 +32,10 @@
         # Always download the image if we have no checksum to compare with.
         force: "{{ expected_checksum is skipped }}"
         backup: true
+      register: result
+      until: result is successful
+      retries: 3
+      delay: 5
   when:
     - image_download_url is not none
     - image_download_url != ""