Grant alert bot reporter access programmatically

Before this commit the alert bot could not create labels on project
with private issue access ALTHOUGH it has `:reporter_access`.

Reason: In order to check project `issues_disabled` rule we check user's
team access level. AFAIK, there's no way to utilize `:reporter_access`.

ee/app/policies/ee/project_policy.rb

@@ -97,8 +97,6 @@ module EE
         prevent :read_project
       end
 
-      rule { alert_bot }.enable :reporter_access
-
       rule { license_block }.policy do
         prevent :create_issue
         prevent :create_merge_request_in
@@ -266,7 +264,8 @@ module EE
 
     override :lookup_access_level!
     def lookup_access_level!
-      return ::GroupMember::NO_ACCESS if needs_new_sso_session?
+      return ::Gitlab::Access::NO_ACCESS if needs_new_sso_session?
+      return ::Gitlab::Access::REPORTER if alert_bot?
 
       super
     end

ee/spec/policies/project_policy_spec.rb

@@ -828,6 +828,12 @@ describe ProjectPolicy do
     let(:current_user) { User.alert_bot }
 
     it { is_expected.to be_allowed(:reporter_access) }
+
+    context 'within a private project' do
+      let(:project) { create(:project, :private) }
+
+      it { is_expected.to be_allowed(:admin_issue) }
+    end
   end
 
   context 'commit_committer_check is not enabled by the current license' do