Add unstable tag on some replication tests

The tempest tests `test_promote_out_of_sync_share_replica` and
`test_resync_share_replica` are concurrency-prone.

Theses tests are trying to determine something that shouldn't really
be a problem and may require to over-engineer the APIs to solve it.

Closes-Bug: #1631314
Change-Id: I4519147f2c1e7f4ea060d83b1a34d0a85dca9687

manila_tempest_tests/tests/api/admin/test_replication.py

@@ -83,6 +83,7 @@ class ReplicationAdminTest(base.BaseSharesMixedTest):
         return [replica['id'] for replica in replica_list
                 if replica['replica_state'] == r_state]
 
+    @decorators.unstable_test(bug='1631314')
     @decorators.idempotent_id('0213cdfd-6a0f-4f24-a154-69796888a64a')
     @tc.attr(base.TAG_POSITIVE, base.TAG_BACKEND)
     @ddt.data(
@@ -211,6 +212,7 @@ class ReplicationAdminTest(base.BaseSharesMixedTest):
             self.admin_client, replica['id'], constants.STATUS_ERROR,
             resource_name='share_replica', status_attr='replica_state')
 
+    @decorators.unstable_test(bug='1631314')
     @decorators.idempotent_id('2969565a-85e8-4c61-9dfb-cc7f7ca9f6dd')
     @tc.attr(base.TAG_POSITIVE, base.TAG_BACKEND)
     @ddt.data(

manila_tempest_tests/tests/api/test_replication_negative.py

@@ -137,6 +137,7 @@ class ReplicationNegativeTest(ReplicationNegativeBase):
                           self.shares_v2_client.delete_share,
                           self.share1["id"])
 
+    @decorators.unstable_test(bug='1631314')
     @decorators.idempotent_id('b9c2e57b-f1ae-475c-9d0b-df75dbe93b61')
     @tc.attr(base.TAG_NEGATIVE, base.TAG_API_WITH_BACKEND)
     def test_promote_out_of_sync_share_replica(self):

releasenotes/notes/bug-1631314-1509db08c75ff645.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    `Bug #1631314 <https://bugs.launchpad.net/manila/+bug/1631314>`_:
+    Fixed an issue on unstable replication tests.