Update Gerrit permissions for global service users (built at http://cl/893733512)

Added permissions:
  Section [refs/heads/*]:
    Read:
      ALLOW: SLSA Policy Verification Service Accounts
    label-SLSA-Policy-Verified:
      ALLOW: SLSA Policy Verification Service Accounts

groups

diff --git a/groups b/groups
index cca152c..3b289bc 100644
--- a/groups
+++ b/groups
@@ -1,5 +1,6 @@
 # UUID                                                        	Group Name
 #
+7b2cd19df59753cdc744285a3dfdcece9582b815                      	SLSA Policy Verification Service Accounts
 global:Anonymous-Users                                        	Anonymous Users
 global:Project-Owners                                         	Project Owners
 global:Registered-Users                                       	Registered Users

project.config

diff --git a/project.config b/project.config
index 5a85f77..727a2ad 100644
--- a/project.config
+++ b/project.config
@@ -42,6 +42,8 @@
 	editTopicName = +force group mdb/gem5-gadmins
 	label-Verified = -1..+1 group mdb/kokoro
 	label-Verified = -1..+1 group mdb/kokoro-dedicated
+	label-SLSA-Policy-Verified = -1..+1 group SLSA Policy Verification Service Accounts
+	Read = group SLSA Policy Verification Service Accounts
 [access "refs/meta/config"]
 	exclusiveGroupPermissions = read
 	read = group Project Owners