Update/remove flag-metadata entries

The flags "autofill-always-show-server-cards-in-sync-transport" and
"fcm-invalidations" were already removed, so just remove the metadata
entries as well. The flags "enable-sync-uss-nigori" and
"enable-sync-uss-passwords" are still needed, so extend them to M80
for now.

Bug: none
Change-Id: I85e28c4d961d1b5ff0416be964714c880d22c26c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1859957
Auto-Submit: Marc Treib <treib@chromium.org>
Reviewed-by: Jan Krcal <jkrcal@chromium.org>
Commit-Queue: Jan Krcal <jkrcal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705539}

chrome/browser/flag-metadata.json

@@ -228,11 +228,6 @@
     "owners": [ "aneeshali@google.com", "annelim@google.com", "jsaul@google.com" ],
     "expiry_milestone": 87
   },
-  {
-    "name": "autofill-always-show-server-cards-in-sync-transport",
-    "owners": [ "sebsg" ],
-    "expiry_milestone": 74
-  },
   {
     "name": "autofill-assistant-chrome-entry",
     "owners": [ "gogerald,wuandy" ],
@@ -1777,12 +1772,12 @@
   {
     "name": "enable-sync-uss-nigori",
     "owners": [ "mmoskvitin@google.com", "//components/sync/OWNERS" ],
-    "expiry_milestone": 78
+    "expiry_milestone": 80
   },
   {
     "name": "enable-sync-uss-passwords",
     "owners": [ "mamir", "//components/sync/OWNERS" ],
-    "expiry_milestone": 77
+    "expiry_milestone": 80
   },
   {
     "name": "enable-system-webapps",
@@ -2098,11 +2093,6 @@
     "owners": [ "//extensions/OWNERS", "pbos" ],
     "expiry_milestone": 82
   },
-  {
-    "name": "fcm-invalidations",
-    "owners": [ "melandory", "chrome-sync-dev@google.com" ],
-    "expiry_milestone": 76
-  },
   {
     "name": "file-handling-api",
     "owners": ["harrisjay@chromium.org", "raymes@chromium.org"],