ServiceBootstrap unit test fix

[vdiskg]

on jdk11 the method java.util.ServiceLoader#load called the check method java.util.ServiceLoader#checkCaller
the private interface cause the error service type not accessible to xxx

    private static void checkCaller(Class<?> caller, Class<?> svc) {
        ...
        // Check access to the service type
        Module callerModule = caller.getModule();
        int mods = svc.getModifiers();
        if (!Reflection.verifyMemberAccess(caller, svc, null, mods)) {
            fail(svc, "service type not accessible to " + callerModule);
        }
        ...
    }

[nobodyiam]

How about this?

Suggested change

	public interface Interface1 {
	interface Interface1 {

[vdiskg]

That's right, package-private is enough for ServiceLoader

[nobodyiam]

LGTM