Revert of [Payments] Update autofill/payments spacings

chrome/android/java/res/layout/payment_request_editor.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2016 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
 <!-- PaymentRequestUI editor dialog. -->
 <LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:chrome="http://schemas.android.com/apk/res-auto"
     android:orientation="vertical" >
@@ skipping 13 matching lines @@
     <org.chromium.chrome.browser.payments.ui.FadingEdgeScrollView
         android:id="@+id/scroll_view"
         android:layout_height="0dp"
         android:layout_width="match_parent"
         android:layout_weight="1" >
 
         <LinearLayout
             android:id="@+id/contents"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:paddingStart="@dimen/pref_autofill_content_spacing"
-            android:paddingEnd="@dimen/pref_autofill_content_spacing"
-            android:orientation="vertical" />
+            android:paddingStart="@dimen/payments_section_large_spacing"
+            android:paddingEnd="@dimen/payments_section_large_spacing"
+            android:orientation="vertical" >
+
+            <TextView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="8dp"
+                android:layout_marginBottom="16dp"
+                android:textColor="@color/descriptive_text_color"
+                android:textSize="12sp"
+                android:text="@string/payments_required_field_message" />
+
+        </LinearLayout>
 
     </org.chromium.chrome.browser.payments.ui.FadingEdgeScrollView>
 
     <!-- CANCEL and DONE buttons. -->
     <org.chromium.chrome.browser.widget.DualControlLayout
         android:id="@+id/button_bar"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:padding="@dimen/payments_section_large_spacing"
         android:background="@android:color/white"
         chrome:stackedMargin="@dimen/infobar_margin_between_stacked_buttons"
         chrome:primaryButtonText="@string/done"
         chrome:secondaryButtonText="@string/cancel" />
 
 </LinearLayout>