Fix case issue

Author: loic-sharma

lib/ui/platform_dispatcher.dart

@@ -182,7 +182,7 @@ class PlatformDispatcher {
   ///
   /// While the properties on the referenced [FlutterView] may change,
   /// the reference itself is guaranteed to never change over the lifetime
-  /// of the application: If this property is null at startup, it will remain
+  /// of the application: if this property is null at startup, it will remain
   /// so throughout the entire lifetime of the application. If it points to a
   /// specific [FlutterView], it will continue to point to the same view until
   /// the application is shut down (although the engine may replace or remove

lib/web_ui/lib/src/engine/platform_dispatcher.dart

@@ -162,7 +162,7 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
   ///
   /// While the properties on the referenced [FlutterView] may change,
   /// the reference itself is guaranteed to never change over the lifetime
-  /// of the application: If this property is null at startup, it will remain
+  /// of the application: if this property is null at startup, it will remain
   /// so throughout the entire lifetime of the application. If it points to a
   /// specific [FlutterView], it will continue to point to the same view until
   /// the application is shut down (although the engine may replace or remove