ManagedChannel not shut down properly - spring-boot

Question

The error I put below, where a ManagedChannel was not shut down properly. I have read this issue, but couldn't find a solution: . So the question here is: what do I need to shut down and how?
I have basically completely copied the code from Google's docs. I will put the faulty class below the error as well. I have tried finding a "shutdown" method on all of the variables, but there aren't any, so I'm not sure what I should do.
2021-01-18 19:21:59.443 ERROR 1 --- [nio-8080-exec-8] i.g.i.ManagedChannelOrphanWrapper : *~*~*~ Channel ManagedChannelImpl{logId=157, target=homegraph.googleapis.com} was not shutdown properly!!! ~*~*~* │
│ Make sure to call shutdown()/shutdownNow() and wait until awaitTermination() returns true. │
│ java.lang.RuntimeException: ManagedChannel allocation site │
│ at io.grpc.internal.ManagedChannelOrphanWrapper$ManagedChannelReference.<init>(ManagedChannelOrphanWrapper.java:103) ~[grpc-core-1.15.1.jar!/:1.15.1] │
│ at io.grpc.internal.ManagedChannelOrphanWrapper.<init>(ManagedChannelOrphanWrapper.java:53) ~[grpc-core-1.15.1.jar!/:1.15.1] │
│ at io.grpc.internal.ManagedChannelOrphanWrapper.<init>(ManagedChannelOrphanWrapper.java:44) ~[grpc-core-1.15.1.jar!/:1.15.1] │
│ at io.grpc.internal.AbstractManagedChannelImplBuilder.build(AbstractManagedChannelImplBuilder.java:410) ~[grpc-core-1.15.1.jar!/:1.15.1] │
│ at com.google.actions.api.smarthome.SmartHomeApp.reportState(SmartHomeApp.kt:126) ~[actions-on-google-1.8.0.jar!/:na] │
│ at ordina.engie.googlehome.google.services.ReportStateService.reportState(ReportStateService.java:41) ~[classes!/:0.0.1-SNAPSHOT] │
│ at ordina.engie.googlehome.toon.controllers.ToonController.reportToGoogle(ToonController.java:27) ~[classes!/:0.0.1-SNAPSHOT]
The method where the error happens:
public void reportState(String requestId, String commonName, ThermostatInfo thermostatInfo) {
Value deviceStates =
Value.newBuilder()
.setStructValue(
Struct.newBuilder()
.putFields(HOME_RESPONSE_KEY_ONLINE, Value.newBuilder().setBoolValue(true).build())
.putFields(HOME_RESPONSE_KEY_MODE, Value.newBuilder().setStringValue(smartHomeHelperService.calculateThermostatMode(thermostatInfo)).build())
.putFields(HOME_RESPONSE_KEY_SETPOINT, Value.newBuilder().setNumberValue(thermostatInfo.getCurrentSetpoint()).build())
.putFields(HOME_RESPONSE_KEY_AMBIENT, Value.newBuilder().setNumberValue(thermostatInfo.getCurrentDisplayTemp()).build())
.build())
.build();
Struct requestStates = Struct.newBuilder().putFields(commonName, deviceStates).build();
HomeGraphApiServiceProto.ReportStateAndNotificationResponse response =
engieSmartHomeAppService.reportState(
HomeGraphApiServiceProto.ReportStateAndNotificationRequest.newBuilder()
.setRequestId(requestId)
.setAgentUserId(commonName)
.setPayload(
HomeGraphApiServiceProto.StateAndNotificationPayload.newBuilder()
.setDevices(
HomeGraphApiServiceProto.ReportStateAndNotificationDevice.newBuilder()
.setStates(requestStates)
.build())
.build())
.build());
}