init: Update `bugreport` service definition

```
host_init_verifier: vendor/lineage/prebuilt/common/etc/init/init.lineage-system_ext.rc: 6: No user specified for service 'bugreport', so it would have been root.
host_init_verifier: Failed to parse init scripts with 1 error(s).
```

Change-Id: I0bd03cb673096f1e686ede59c7db70ab1e581ec1