in_opentelemetry: Fixed the event type so OTel metrics are properly routed

Signed-off-by: Leonardo Alminana <[email protected]>

Author: Leonardo Alminana

plugins/in_opentelemetry/opentelemetry.c

@@ -172,4 +172,5 @@ struct flb_input_plugin in_opentelemetry_plugin = {
     .cb_exit      = in_opentelemetry_exit,
     .config_map   = config_map,
     .flags        = FLB_INPUT_NET,
+    .event_type   = FLB_INPUT_METRICS
 };