Update expiry for some sync-related flags

Still required, thus extended to M83:
enable-sync-device-info-in-transport-mode
enable-sync-uss-nigori
enable-sync-uss-passwords

Flags already removed, thus removing metadata entries:
enable-sync-uss-bookmarks
sync-support-secondary-account

Bug: none
Change-Id: I05426ec0909a3b24c856aa4ce79200f42123901c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1917769
Auto-Submit: Marc Treib <treib@chromium.org>
Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715655}

chrome/browser/flag-metadata.json

@@ -1878,22 +1878,17 @@
   {
     "name": "enable-sync-device-info-in-transport-mode",
     "owners": ["//components/sync/OWNERS", "//chrome/browser/sharing/OWNERS"],
-    "expiry_milestone": 81
-  },
-  {
-    "name": "enable-sync-uss-bookmarks",
-    "owners": [ "mamir", "//components/sync/OWNERS" ],
-    "expiry_milestone": 80
+    "expiry_milestone": 83
   },
   {
     "name": "enable-sync-uss-nigori",
     "owners": [ "mmoskvitin@google.com", "//components/sync/OWNERS" ],
-    "expiry_milestone": 80
+    "expiry_milestone": 83
   },
   {
     "name": "enable-sync-uss-passwords",
     "owners": [ "mamir", "//components/sync/OWNERS" ],
-    "expiry_milestone": 80
+    "expiry_milestone": 83
   },
   {
     "name": "enable-system-webapps",
@@ -3351,11 +3346,6 @@
     "owners": [ "joaodasilva" ],
     "expiry_milestone": 80
   },
-  {
-    "name": "sync-support-secondary-account",
-    "owners": [ "treib", "//components/sync/OWNERS" ],
-    "expiry_milestone": 80
-  },
   {
     "name": "sync-wifi-configurations",
     "owners": ["jonmann", "cros-system-services@google.com"],