[web] Reland: Enable the new rich paragraph implementation

Author: mdebbar

lib/web_ui/lib/src/engine/web_experiments.dart

@@ -45,7 +45,7 @@ class WebExperiments {
 
   static const bool _defaultUseCanvasRichText = const bool.fromEnvironment(
     'FLUTTER_WEB_USE_EXPERIMENTAL_CANVAS_RICH_TEXT',
-    defaultValue: false,
+    defaultValue: true,
   );
 
   bool _useCanvasRichText = _defaultUseCanvasRichText;

lib/web_ui/test/engine/web_experiments_test.dart

@@ -11,7 +11,7 @@ import 'package:test/test.dart';
 import 'package:ui/src/engine.dart';
 
 const bool _defaultUseCanvasText = true;
-const bool _defaultUseCanvasRichText = false;
+const bool _defaultUseCanvasRichText = true;
 
 void main() {
   internalBootstrapBrowserTest(() => testMain);