CrashLoopBackOff on event-exporter-gke

I am running a cluster on GKE with `1.16.9-gke.6`.

Since a few days now I observed a `CrashLoopBackOff` error on `event-exporter-gke`. This resource has two containers with the following logs:

- `event-exporter`:

```
27:45.46110173Z E0711 17:27:45.460910 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:46.465727197Z E0711 17:27:46.465531 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:47.482583742Z E0711 17:27:47.472515 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:48.476815862Z E0711 17:27:48.476649 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:49.481642225Z E0711 17:27:49.481446 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:50.486296623Z E0711 17:27:50.486133 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:51.49117627Z E0711 17:27:51.491001 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:52.495502303Z E0711 17:27:52.495371 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:53.520458294Z E0711 17:27:53.520240 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:54.525113683Z E0711 17:27:54.524944 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:55.530228116Z E0711 17:27:55.529988 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:56.535040461Z E0711 17:27:56.534804 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:57.539863055Z E0711 17:27:57.539649 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:58.545027736Z E0711 17:27:58.544888 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
2020-07-11T17:27:59.549523735Z E0711 17:27:59.549323 1 reflector.go:190] github.com/GoogleCloudPlatform/k8s-stackdriver/event-exporter/watchers/watcher.go:50: Failed to list *v1.Event: Unauthorized
```

- `prometheus-to-sd-exporter`:

```
2020-07-11T17:25:20.669963067Z F0711 17:25:20.669825 1 main.go:123] Failed to get GCE config: error while getting instance (node) name: metadata: GCE metadata "instance/name" not defined
```