Add a second type paramter, U, on mapNestedViews; U is the type of th…

…e argument of [callback]. Generated template.dart files fill in a type for the argument of [callback], so using dynamic here results in a "uses dynamic as bottom" error.

See discussion here: dart-lang/sdk#29630

PiperOrigin-RevId: 183131552

angular/lib/src/core/linker/view_container.dart

@@ -155,7 +155,7 @@ class ViewContainer extends ComponentLoader implements ViewContainerRef {
     }
   }
 
-  List<T> mapNestedViews<T>(List<T> Function(dynamic) callback) {
+  List<T> mapNestedViews<T, U extends AppView>(List<T> Function(U) callback) {
     final nestedViews = this.nestedViews;
     if (nestedViews == null || nestedViews.isEmpty) {
       return const [];