flags: assign reader mode flags

This change assigns:
  enable-reader-mode-in-cct
  reader-mode-heuristics

to mdjones and bumps the expiration to M78 while we investigate whether to keep
these longer-term.

Bug: None
Change-Id: I717dac7bdabfb76ed456a2906f34244a62f67088
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1628044
Auto-Submit: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663269}
diff --git a/chrome/browser/flag-metadata.json b/chrome/browser/flag-metadata.json
index 378b4b26..ea1db31 100644
--- a/chrome/browser/flag-metadata.json
+++ b/chrome/browser/flag-metadata.json
@@ -1421,8 +1421,8 @@
   },
   {
     "name": "enable-reader-mode-in-cct",
-    // "owners": [ "your-team" ],
-    "expiry_milestone": 76
+    "owners": [ "mdjones" ],
+    "expiry_milestone": 78
   },
   {
     "name": "enable-reopen-tab-in-product-help",
@@ -2619,8 +2619,8 @@
   },
   {
     "name": "reader-mode-heuristics",
-    // "owners": [ "your-team" ],
-    "expiry_milestone": 76
+    "owners": [ "mdjones" ],
+    "expiry_milestone": 78
   },
   {
     "name": "reduced-referrer-granularity",