CI: run S3 cross-compat tests as part of DSVM jobs

We're increasingly trying to move toward having S3 tests that pass
against both AWS and Swift. Especially as we move to replace our old
boto(2) tests, it would be nice to have the replacements be cross-
compatible from the get-go.

However, there was previously a risk in leaning too-heavily on that
test suite: only the functional test suite would be exercised in the
gate with Keystone. Now, run both test suites to ensure we don't
leave implementation gaps in s3token.

Change-Id: I873c32107b4174bd2968097b5fe96d97f260a256

.zuul.yaml

@@ -242,7 +242,7 @@
         COLUMNS: 240
       tox_constraints_file: '{{ ansible_user_dir }}/src/opendev.org/openstack/requirements/upper-constraints.txt'
       # This tox env get run twice; once for Keystone and once for tempauth
-      tox_envlist: func
+      tox_envlist: func,s3api
       devstack_localrc:
         SWIFT_HASH: changeme
         # We don't need multiple replicas to run purely functional tests.

roles/dsvm-additional-middlewares/tasks/main.yaml

@@ -21,6 +21,14 @@
     value: example.com
   become: true
 
+- name: Turn on s3_acl_tests_disabled in test.conf (for Keystone tests)
+  ini_file:
+    path: /etc/swift/test.conf
+    section: s3api_test
+    option: s3_acl_tests_disabled
+    value: true
+  become: true
+
 - name: Set storage_domain in test/sample.conf (for tempauth tests)
   ini_file:
     path: "{{ ansible_env.HOME }}/{{ zuul.project.src_dir }}/test/sample.conf"
@@ -29,6 +37,14 @@
     value: example.com
   become: true
 
+- name: Turn on s3_acl_tests_disabled in test/sample.conf (for tempauth tests)
+  ini_file:
+    path: "{{ ansible_env.HOME }}/{{ zuul.project.src_dir }}/test/sample.conf"
+    section: s3api_test
+    option: s3_acl_tests_disabled
+    value: true
+  become: true
+
 - name: Enable object versioning
   ini_file:
     path: /etc/swift/proxy-server.conf