Don't resolve ConfigurationProperties placeholders

Revert commit 3ad43e0d to give us
a little more time to consider how this will impact tooling.

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessor.java

@@ -289,7 +289,6 @@ public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProc
 			String targetName = (StringUtils.hasLength(annotation.value()) ? annotation
 					.value() : annotation.prefix());
 			if (StringUtils.hasLength(targetName)) {
-				targetName = this.environment.resolvePlaceholders(targetName);
 				factory.setTargetName(targetName);
 			}
 		}

spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessorTests.java

@@ -148,16 +148,6 @@ public class ConfigurationPropertiesBindingPostProcessorTests {
 				equalTo("foo"));
 	}
 
-	@Test
-	public void placeholderInPrefix() throws Exception {
-		this.context = new AnnotationConfigApplicationContext();
-		EnvironmentTestUtils.addEnvironment(this.context, "foo:spam", "spam.foo:bar");
-		this.context.register(PlaceholderPrefixConfiguration.class);
-		this.context.refresh();
-		assertThat(this.context.getBean(PlaceholderPrefixConfiguration.class).getFoo(),
-				equalTo("bar"));
-	}
-
 	@Test
 	public void placeholderResolutionWithCustomLocation() throws Exception {
 		this.context = new AnnotationConfigApplicationContext();
@@ -383,22 +373,6 @@ public class ConfigurationPropertiesBindingPostProcessorTests {
 
 	}
 
-	@EnableConfigurationProperties
-	@ConfigurationProperties(prefix = "${foo:bar}")
-	public static class PlaceholderPrefixConfiguration {
-
-		private String foo;
-
-		public String getFoo() {
-			return this.foo;
-		}
-
-		public void setFoo(String foo) {
-			this.foo = foo;
-		}
-
-	}
-
 	@EnableConfigurationProperties
 	@ConfigurationProperties(locations = "custom-location.yml")
 	public static class CustomConfigurationLocation {