[flags, webnfc] Assign ownership for webnfc flag.

flags: Assign ownership of the "enable-webnfc" flag.

Setting expiry milestone to be M79.
We will update the status if there are any changes.

Bug: 520391
Change-Id: I64e46a4da6abcb4c47947c4928f4ae981880a369
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1505496
Commit-Queue: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638123}

chrome/browser/flag-metadata.json

@@ -1927,8 +1927,8 @@
   },
   {
     "name": "enable-webnfc",
-    // "owners": [ "your-team" ],
-    "expiry_milestone": 76
+    "owners": [ "rijubrata.bhaumik@intel.com","reillyg" ],
+    "expiry_milestone": 79
   },
   {
     "name": "enable-webrtc-h264-with-openh264-ffmpeg",