Change acl for mistral-lib

According to https://docs.openstack.org/infra/manual/creators.html#add-gerrit-permissions,
mistral-lib needs to have its own acl definition as a library, in order
to be tagged and released properly.

Needed-By: Icec6d1a3c483a30e9e3fa3175ed0233053c69daa

Change-Id: I374b51c6c8991e59304afd402dad9f1364e71770

gerrit/acls/openstack/mistral-lib.config

@@ -0,0 +1,15 @@
+[access "refs/heads/*"]
+abandon = group mistral-core
+create = group mistral-release
+label-Code-Review = -2..+2 group mistral-core
+label-Workflow = -1..+1 group mistral-core
+
+[access "refs/tags/*"]
+pushSignedTag = group library-release
+
+[receive]
+requireChangeId = true
+requireContributorAgreement = true
+
+[submit]
+mergeContent = true

gerrit/projects.yaml

@@ -4863,7 +4863,6 @@
   description: Mistral Library with shared routines and utilities.
   groups:
     - mistral
-  acl-config: /home/gerrit2/acls/openstack/mistral.config
 - project: openstack/mistral-specs
   description: OpenStack Workflow (Mistral) Specifications
   groups: