[autofill] Enable deletion of disused autofill data

This CL turns on deletion of disused address and credit card data. This
data has already been suppressed (i.e., not suggested) for the last two
quarters.

As a result of this CL:

* Address data will be deleted 13 months after last use (it stops being
  suggested 6 months after last use).

* Local credit card data is deleted 13 months after the later of expiry
  or last use; it stops being suggested 6 months after expiry/last use).

Cards coming from Google Pay stop being synced 12 months after expiry. Their
lifetime is independent of this CL.

Bug: 868406
Change-Id: I6113f6f96e7854b8684e3258f372c91475aa96a8
Reviewed-on: https://chromium-review.googlesource.com/1101168
Commit-Queue: Roger McFarlane <rogerm@chromium.org>
Reviewed-by: Roger McFarlane <rogerm@chromium.org>
Reviewed-by: Tatiana Gornak <melandory@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589521}

components/autofill/core/common/autofill_features.cc

@@ -47,10 +47,10 @@ const base::Feature kAutofillCreditCardLocalCardMigration{
     "AutofillCreditCardLocalCardMigration", base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kAutofillDeleteDisusedAddresses{
-    "AutofillDeleteDisusedAddresses", base::FEATURE_DISABLED_BY_DEFAULT};
+    "AutofillDeleteDisusedAddresses", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kAutofillDeleteDisusedCreditCards{
-    "AutofillDeleteDisusedCreditCards", base::FEATURE_DISABLED_BY_DEFAULT};
+    "AutofillDeleteDisusedCreditCards", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Controls whether the credit card downstream keyboard accessory shows
 // the Google Pay logo animation on iOS.