Fix autolayout constraint with label on STPCardFormView

Author: wooj-stripe

Example/UI Examples/UI Examples/Source/SwiftUICardFormView.swift

@@ -16,9 +16,11 @@ struct SwiftUICardFormView: View {
 
     var body: some View {
         VStack {
+            Spacer().layoutPriority(1)
             STPCardFormView.Representable(paymentMethodParams: $paymentMethodParams,
                                           isComplete: $cardFormIsComplete)
                 .padding()
+            Spacer().layoutPriority(1)
             Button(action: {
                 print("Process payment...")
             }, label: {

StripePaymentsUI/StripePaymentsUI/Source/UI Components/STPFormView.swift

@@ -652,7 +652,6 @@ extension STPFormView {
                     equalTo: stackView.bottomAnchor,
                     constant: SectionView.titleVerticalMargin
                 ),
-                bottomAnchor.constraint(equalTo: footerLabel.bottomAnchor),
             ])
 
             // the initial layout of a SectionView will log constraint errors if it has a row with multiple