Return AddExplicitInterfaceImplementation capability from agent

Author: tmat

src/BuiltInTools/HotReloadAgent/HotReloadAgent.cs

@@ -95,6 +95,13 @@ private void GetUpdaterMethodsAndCapabilities(out ApplyUpdateDelegate? applyUpda
         {
             Reporter.Report($"Error retrieving capabilities: {e.Message}", AgentMessageSeverity.Error);
         }
+
+        // .NET Framework runtime does not support adding MethodImpl entries, therefore the capability is not in the baseline capability set.
+        // All other runtimes (.NET and Mono) support it and rather than servicing all of them we include the capability here.
+        if (!string.IsNullOrEmpty(capabilities))
+        {
+            capabilities += " AddExplicitInterfaceImplementation";
+        }
     }
 
     public string Capabilities => _capabilities ?? string.Empty;