msglist: On Android, show reaction chips with Noto Color Emoji font

We should also use this font for Unicode emojis elsewhere, such as
message content, users' names, and so on. But the proper layout of
these chips is especially sensitive to how these emojis get
rendered, and apparently the system emoji font can vary quite a bit
on Android (same link as removed in the TODO):
  zulip#410 (comment)
So we'd like to converge on one font here (at least for Android) as
soon as possible.

Author: chrisbobbe

lib/widgets/emoji_reaction.dart

@@ -198,10 +198,6 @@ const _squareEmojiSize = 17.0;
 ///
 /// Determined experimentally:
 ///   <https://github.com/zulip/zulip-flutter/pull/410#discussion_r1402808701>
-// TODO Actually use Noto Color Emoji. Some Android
-//   phones use Noto Color Emoji automatically, and some don't; e.g., Samsung
-//   has its own emoji font:
-//     <https://github.com/zulip/zulip-flutter/pull/410#discussion_r1408403111>
 const _notoColorEmojiTextSize = 14.5;
 
 /// A [TextScaler] that limits Unicode and image emojis' max scale factor,
@@ -249,7 +245,10 @@ class _UnicodeEmoji extends StatelessWidget {
       case TargetPlatform.windows:
         return Text(
           textScaler: _squareEmojiScalerClamped(context),
-          style: const TextStyle(fontSize: _notoColorEmojiTextSize),
+          style: const TextStyle(
+            fontFamily: 'Noto Color Emoji',
+            fontSize: _notoColorEmojiTextSize,
+          ),
           strutStyle: const StrutStyle(fontSize: _notoColorEmojiTextSize, forceStrutHeight: true),
           parsed);
       case TargetPlatform.iOS: