Fix test failure with indy (#13294)

Author: laurit

instrumentation/spring/spring-boot-actuator-autoconfigure-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/spring/actuator/v2_0/OpenTelemetryMeterRegistryAutoConfiguration.java

@@ -43,7 +43,9 @@ public MeterRegistry otelMeterRegistry() {
 
   @Bean
   // static to avoid "is not eligible for getting processed by all BeanPostProcessors" warning
-  static BeanPostProcessor postProcessCompositeMeterRegistry() {
+  // must be public because this class is injected as a proxy when using non-inlined advice and that
+  // proxy contains only public methods
+  public static BeanPostProcessor postProcessCompositeMeterRegistry() {
     return new BeanPostProcessor() {
       @Override
       public Object postProcessAfterInitialization(Object bean, String beanName) {