Correct usage of String.format(..) (#11704)

Fixes https://github.com/vaadin/framework/issues/11701

server/src/main/java/com/vaadin/util/ReflectTools.java

@@ -32,12 +32,12 @@ import java.lang.reflect.Modifier;
  */
 public class ReflectTools implements Serializable {
 
-    static final String CREATE_INSTANCE_FAILED = "Unable to create an instance of {0}. Make sure it has a no-arg constructor";
-    static final String CREATE_INSTANCE_FAILED_FOR_NON_STATIC_MEMBER_CLASS = "Unable to create an instance of {0}. Make sure the class is static if it is a nested class.";
-    static final String CREATE_INSTANCE_FAILED_ACCESS_EXCEPTION = "Unable to create an instance of {0}. Make sure the class is public and that is has a public no-arg constructor.";
-    static final String CREATE_INSTANCE_FAILED_NO_PUBLIC_NOARG_CONSTRUCTOR = "Unable to create an instance of {0}. Make sure the class has a public no-arg constructor.";
+    static final String CREATE_INSTANCE_FAILED = "Unable to create an instance of '%s'. Make sure it has a no-arg constructor";
+    static final String CREATE_INSTANCE_FAILED_FOR_NON_STATIC_MEMBER_CLASS = "Unable to create an instance of '%s'. Make sure the class is static if it is a nested class.";
+    static final String CREATE_INSTANCE_FAILED_ACCESS_EXCEPTION = "Unable to create an instance of '%s'. Make sure the class is public and that is has a public no-arg constructor.";
+    static final String CREATE_INSTANCE_FAILED_NO_PUBLIC_NOARG_CONSTRUCTOR = "Unable to create an instance of '%s'. Make sure the class has a public no-arg constructor.";
     static final String CREATE_INSTANCE_FAILED_LOCAL_CLASS = "Cannot instantiate local class '%s'. Move class declaration outside the method.";
-    static final String CREATE_INSTANCE_FAILED_CONSTRUCTOR_THREW_EXCEPTION = "Unable to create an instance of {0}. The constructor threw an exception.";
+    static final String CREATE_INSTANCE_FAILED_CONSTRUCTOR_THREW_EXCEPTION = "Unable to create an instance of '%s'. The constructor threw an exception.";
 
     /**
      * Locates the method in the given class. Returns null if the method is not