Respect spring.profiles.active in #addActiveProfile

Prior to this commit, calls to ConfigurableEnvironment#addActiveProfile
would cause any active profile values provided via the
"spring.profiles.active" property to be ignored.

Now these two mechanisms can be used in conjunction and work as
expected.

Issue: SPR-9944

spring-context/src/test/java/org/springframework/context/support/EnvironmentIntegrationTests.java

@@ -17,7 +17,6 @@
 package org.springframework.context.support;
 
 import org.junit.Test;
-
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -34,7 +33,6 @@ import static org.junit.Assert.*;
  */
 public class EnvironmentIntegrationTests {
 
-	@SuppressWarnings("unchecked")
 	@Test
 	public void repro() {
 		ConfigurableApplicationContext parent = new GenericApplicationContext();