[Blazor] Update template to pass in attribute as boolean (#28285)

Description
We introduced a public property as part of #27907 to enable users to opt-in. Turns out that this caused issues since we didn't update the target pack.

As a result, the Razor compiler treats this new property as a regular HTML attribute (of type string) instead of as a boolean.

In turn this causes the template to error at runtime when the application starts.

Customer Impact
Customers using 5.0.1 won't be able to create and run new blazor apps out of the box. They can fix the template code by preceding the true value in the attribute with @ to force the compiler to interpret it as C#. (Which is the same fix we are applying).

Regression?
Yes, 5.0.0. Users were able to create new blazor templates without this issue.

Risk
Low. We've manually validated the fix against a new project from a 5.0.1 template.

Author: javiercn

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorServerWeb-CSharp/App.razor

@@ -1,5 +1,5 @@
 @*#if (NoAuth)
-<Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="true">
+<Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="@true">
     <Found Context="routeData">
         <RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
     </Found>
@@ -11,7 +11,7 @@
 </Router>
 #else
 <CascadingAuthenticationState>
-    <Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="true">
+    <Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="@true">
         <Found Context="routeData">
             <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
         </Found>

src/ProjectTemplates/Web.ProjectTemplates/content/ComponentsWebAssembly-CSharp/Client/App.razor

@@ -1,5 +1,5 @@
 @*#if (NoAuth)
-<Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="true">
+<Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="@true">
     <Found Context="routeData">
         <RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
     </Found>
@@ -11,7 +11,7 @@
 </Router>
 #else
 <CascadingAuthenticationState>
-    <Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="true">
+    <Router AppAssembly="@typeof(Program).Assembly" PreferExactMatches="@true">
         <Found Context="routeData">
             <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)">
                 <NotAuthorized>