NullPointerException with declarative config

[zeitlinger]

Describe the bug

Regression from #14184

	
                        java.lang.NullPointerException	
                            at io.opentelemetry.instrumentation.api.incubator.semconv.net.PeerServiceResolverImpl.<init>(PeerServiceResolverImpl.java:30)	
                            at io.opentelemetry.instrumentation.api.incubator.semconv.net.PeerServiceResolver.create(PeerServiceResolver.java:21)	
                            at io.opentelemetry.instrumentation.api.incubator.config.internal.CommonConfig.<init>(CommonConfig.java:45)	
                            at io.opentelemetry.instrumentation.spring.autoconfigure.internal.properties.InstrumentationConfigUtil.getConfig(InstrumentationConfigUtil.java:41)	
                            at io.opentelemetry.instrumentation.spring.autoconfigure.internal.properties.InstrumentationConfigUtil.configureServerBuilder(InstrumentationConfigUtil.java:36)