DL: Push the enable-display-locking flag expiry to M82.

This patch pushes the flag expiry to M82. At that time, we will
re-evaluate what we need to do.

Change-Id: Ic4dfcaf0c92e10b1e58a3763907d3e302b2f6fc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1919321
Commit-Queue: vmpstr <vmpstr@chromium.org>
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Auto-Submit: vmpstr <vmpstr@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715709}

chrome/browser/flag-metadata.json

@@ -1262,7 +1262,7 @@
   {
     "name": "enable-display-locking",
     "owners": [ "//third_party/blink/renderer/core/display_lock/OWNERS" ],
-    "expiry_milestone": 80
+    "expiry_milestone": 82
   },
   {
     "name": "enable-edu-coexistence",