Image filters should be dict not set

At the moment we generate a set as a filter for image checksums which
lead to AttributeError in SDK:
'set' object has no attribute 'keys'

With that we ensure that supllying checksum does not cause
module crash.

Change-Id: I490f51950592f62c9ad81806593340779bf6dbdb

ci/roles/image/tasks/main.yml

@@ -24,6 +24,13 @@
         path: '{{ tmp_file.path }}'
         size: 1M
 
+    - name: Calculating file checksum
+      ansible.builtin.stat:
+        path: "{{ tmp_file.path }}"
+        checksum_algorithm: sha512
+        get_checksum: true
+      register: image_details
+
     - name: Ensure mock kernel and ramdisk images (defaults)
       openstack.cloud.image:
          cloud: "{{ cloud }}"
@@ -42,6 +49,7 @@
          name: ansible_image
          filename: "{{ tmp_file.path }}"
          is_protected: true
+         checksum: "{{ image_details.stat.checksum }}"
          disk_format: raw
          tags:
            - test

plugins/modules/image.py

@@ -485,7 +485,7 @@ class ImageModule(OpenStackModule):
         if image_name_or_id:
             image = self.conn.get_image(
                 image_name_or_id,
-                filters={(k, self.params[k])
+                filters={k: self.params[k]
                          for k in ['checksum'] if self.params[k] is not None})
 
         changed = False