Use the yaml stdout_callback for better prepare logging

Currently when the tripleo-modify-role runs a shell script which
produces a lot of output, its logged once as a no-newline-blob, and
again as one line per array item. Neither output is easy read, which makes
debugging harder.

This change switches to the yaml stdout_callback, and a verbosity
level which only prints the script output once.

Change-Id: I85fb8ca40e03f077147871fcd85536c0572d526e
Closes-Bug: #1813684

tripleo_common/image/image_uploader.py

@@ -243,8 +243,12 @@ class BaseImageUploader(object):
             action = ansible.AnsiblePlaybookAction(
                 playbook=playbook,
                 work_dir=work_dir,
-                verbosity=3,
-                extra_env_variables=dict(os.environ)
+                verbosity=1,
+                extra_env_variables=dict(os.environ),
+                override_ansible_cfg=(
+                    "[defaults]\n"
+                    "stdout_callback=yaml\n"
+                )
             )
             result = action.run(None)
             log_path = result.get('log_path')

tripleo_common/tests/image/test_image_uploader.py

@@ -799,8 +799,12 @@ class TestDockerImageUploader(base.TestCase):
         mock_ansible.assert_called_once_with(
             playbook=playbook,
             work_dir=mock.ANY,
-            verbosity=3,
-            extra_env_variables=mock.ANY
+            verbosity=1,
+            extra_env_variables=mock.ANY,
+            override_ansible_cfg=(
+                "[defaults]\n"
+                "stdout_callback=yaml\n"
+            )
         )
         self.dockermock.return_value.tag.assert_not_called()
         self.dockermock.return_value.push.assert_called_once_with(
@@ -1100,8 +1104,12 @@ class TestSkopeoImageUploader(base.TestCase):
         mock_ansible.assert_called_once_with(
             playbook=playbook,
             work_dir=mock.ANY,
-            verbosity=3,
-            extra_env_variables=mock.ANY
+            verbosity=1,
+            extra_env_variables=mock.ANY,
+            override_ansible_cfg=(
+                "[defaults]\n"
+                "stdout_callback=yaml\n"
+            )
         )
 
     @mock.patch('tripleo_common.image.image_uploader.'