flags: Update expiry milestone for OOPR and SurfaceControl.

OOPR is still in the process of being launched on desktop platforms and
SurfaceControl will be rolled out with Android Q release.

R=ellyjones@chromium.org

Change-Id: I28f9c3f3c18c1e33dcd80bda768d93e948f4b194
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1761321
Auto-Submit: Khushal <khushalsagar@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688500}

chrome/browser/flag-metadata.json

@@ -1442,7 +1442,7 @@
   {
     "name": "enable-oop-rasterization",
     "owners": [ "enne", "khushalsagar" ],
-    "expiry_milestone": 76
+    "expiry_milestone": 80
   },
   {
     "name": "enable-parallel-downloading",
@@ -1658,7 +1658,7 @@
   {
     "name": "enable-surfacecontrol",
     "owners": [ "khushalsagar" ],
-    "expiry_milestone": 76
+    "expiry_milestone": 80
   },
   {
     "name": "enable-surfaces-for-videos",