Skip running any approval migrations for FOSS

Any approval migrations contain the code that
exists only in EE version
That is why we need to skip the running for
the FOSS version

db/post_migrate/20190905091812_schedule_project_any_approval_rule_migration.rb

@@ -22,6 +22,8 @@ class ScheduleProjectAnyApprovalRuleMigration < ActiveRecord::Migration[5.2]
   end
 
   def up
+    return unless Gitlab.ee?
+
     add_concurrent_index :projects, :id,
       name: 'tmp_projects_with_approvals_before_merge',
       where: 'approvals_before_merge <> 0'

db/post_migrate/20190905091831_schedule_merge_request_any_approval_rule_migration.rb

@@ -22,6 +22,8 @@ class ScheduleMergeRequestAnyApprovalRuleMigration < ActiveRecord::Migration[5.2
   end
 
   def up
+    return unless Gitlab.ee?
+
     add_concurrent_index :merge_requests, :id,
       name: 'tmp_merge_requests_with_approvals_before_merge',
       where: 'approvals_before_merge <> 0'

ee/spec/migrations/schedule_merge_request_any_approval_rule_migration_spec.rb

@@ -48,4 +48,22 @@ describe ScheduleMergeRequestAnyApprovalRuleMigration, :migration, :sidekiq do
       end
     end
   end
+
+  context 'for FOSS version' do
+    before do
+      allow(Gitlab).to receive(:ee?).and_return(false)
+    end
+
+    it 'does not schedule any jobs' do
+      create_merge_request(2)
+
+      Sidekiq::Testing.fake! do
+        Timecop.freeze do
+          migrate!
+
+          expect(BackgroundMigrationWorker.jobs.size).to eq(0)
+        end
+      end
+    end
+  end
 end

ee/spec/migrations/schedule_project_any_approval_rule_migration_spec.rb

@@ -43,4 +43,22 @@ describe ScheduleProjectAnyApprovalRuleMigration, :migration, :sidekiq do
       end
     end
   end
+
+  context 'for FOSS version' do
+    before do
+      allow(Gitlab).to receive(:ee?).and_return(false)
+    end
+
+    it 'does not schedule any jobs' do
+      create_project(2)
+
+      Sidekiq::Testing.fake! do
+        Timecop.freeze do
+          migrate!
+
+          expect(BackgroundMigrationWorker.jobs.size).to eq(0)
+        end
+      end
+    end
+  end
 end