Rename TransactionManagementConfigurer callback

Renamed TransactionManagementConfigurer#createTransactionManager()
to #annotationDrivenTransactionManager() to better reflect the fact
that the implemented method is optionally eligible for @Bean annotation.

See Javadoc for details.

org.springframework.transaction/src/test/java/org/springframework/transaction/annotation/EnableTransactionManagementTests.java

@@ -127,7 +127,7 @@ public class EnableTransactionManagementTests {
 			return new CallCountingTransactionManager();
 		}
 
-		public PlatformTransactionManager createTransactionManager() {
+		public PlatformTransactionManager annotationDrivenTransactionManager() {
 			return txManager2();
 		}
 	}