Fix timezone mix up in specs

Converting times with timezones to string was ignoring the timezone and this making the start date be before the end date in this spec

engines/order_management/spec/services/order_management/reports/enterprise_fee_summary/parameters_spec.rb

@@ -39,7 +39,7 @@ describe OrderManagement::Reports::EnterpriseFeeSummary::Parameters do
       end
 
       describe "requiring start_at to be before end_at" do
-        let(:now) { Time.zone.now }
+        let(:now) { Time.zone.now.utc }
 
         it "adds error when start_at is after end_at" do
           allow(subject).to receive(:start_at) { now.to_s }