Enable the EnablePhysicalWeb flag by default on Chrome for iOS

ios/chrome/browser/experimental_flags.mm

Index: ios/chrome/browser/experimental_flags.mm
diff --git a/ios/chrome/browser/experimental_flags.mm b/ios/chrome/browser/experimental_flags.mm
index 83cd53180ee5d9b6540beb9046ce15b558451af0..bec0a41ef96c0a3dde680fde627557102143ac30 100644
--- a/ios/chrome/browser/experimental_flags.mm
+++ b/ios/chrome/browser/experimental_flags.mm
@@ -214,11 +214,12 @@ bool IsPhysicalWebEnabled() {
     return false;
   }
 
-  // Check if the finch experiment is turned on
+  // Check if the Finch experiment is turned on.
   std::string group_name =
       base::FieldTrialList::FindFullName("PhysicalWebEnabled");
-  return base::StartsWith(group_name, "Enabled",
-                          base::CompareCase::INSENSITIVE_ASCII);
+  // The feature is enabled by default.
+  return !base::StartsWith(group_name, "Disabled",
+                           base::CompareCase::INSENSITIVE_ASCII);
 }
 
 bool IsReaderModeEnabled() {