[Payments] Format expiration month dropdown key format to the stored format in Autofill

chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java
index 4413a88e937345a60eefe6bdef205bb0cf2b574c..bf65b3f30774f461104e63cb88f4ac11bd4cd081 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/CardEditor.java
@@ -575,7 +575,7 @@ public class CardEditor extends EditorBase<AutofillPaymentInstrument>
         List<DropdownKeyValue> result = new ArrayList<>();
 
         Locale locale = Locale.getDefault();
-        SimpleDateFormat keyFormatter = new SimpleDateFormat("M", locale);
+        SimpleDateFormat keyFormatter = new SimpleDateFormat("MM", locale);
         SimpleDateFormat valueFormatter = new SimpleDateFormat("MMMM (MM)", locale);
 
         calendar.set(Calendar.DAY_OF_MONTH, 1);