Only invoke getInterfaceMethodIfPossible() when security manager is used

Prior to this commit, AbstractAutowireCapableBeanFactory's
invokeCustomInitMethod() method invoked
ClassUtils.getInterfaceMethodIfPossible() even if the security manager
was not being used.

This commit ensures that getInterfaceMethodIfPossible() is only invoked
if the security manager is used.

Closes gh-23323

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -1882,9 +1882,10 @@ protected void invokeCustomInitMethod(String beanName, final Object bean, RootBe
 		if (logger.isTraceEnabled()) {
 			logger.trace("Invoking init method  '" + initMethodName + "' on bean with name '" + beanName + "'");
 		}
-		Method methodToInvoke = ClassUtils.getInterfaceMethodIfPossible(initMethod);
 
 		if (System.getSecurityManager() != null) {
+			Method methodToInvoke = ClassUtils.getInterfaceMethodIfPossible(initMethod);
+
 			AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
 				ReflectionUtils.makeAccessible(methodToInvoke);
 				return null;