Update autofill flags with current owner and milestone

Two flags are still needed until at least M-79. I now maintain what they
guard.

Bug: None
Change-Id: If5d7c766b29c3e3ddeeeee31c7b4cb8e25a7c7ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1776037Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Friedrich [CET] <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691999}

chrome/browser/flag-metadata.json

@@ -255,8 +255,8 @@
   },
   {
     "name": "autofill-keyboard-accessory-view",
-    "owners": [ "ftirelo" ],
-    "expiry_milestone": 74
+    "owners": [ "fhorschig@chromium.org" ],
+    "expiry_milestone": 79
   },
   {
     "name": "autofill-no-local-save-on-unmask-success",
@@ -946,8 +946,8 @@
   },
   {
     "name": "enable-autofill-manual-fallback",
-    "owners": [ "tmartino@chromium.org" ],
-    "expiry_milestone": 78
+    "owners": [ "fhorschig@chromium.org" ],
+    "expiry_milestone": 79
   },
   {
     "name": "enable-autofill-refresh-style",