Fix ambiguous static import in TestPropertySourceUtilsTests

Author: nkjackzhang

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

@@ -32,7 +32,7 @@
 import org.springframework.mock.env.MockPropertySource;
 import org.springframework.test.context.TestPropertySource;
 
-import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.startsWith;
 import static org.junit.Assert.*;
 import static org.mockito.Matchers.*;