Unexpected timestamp type warning in collector pods forwarding logs to Splunk in RHOCP 4 type

Issue

• Vector pods show the below warning log:

  WARN sink{component_kind="sink" component_id=splunk_receiver component_type=splunk_hec_logs component_name=splunk_receiver}: vector::internal_events::splunk_hec::sink: Timestamp was an unexpected type. Deferring to Splunk to set the timestamp. invalid_type="string" internal_log_rate_limit=true
  WARN sink{component_kind="sink" component_id=splunk_receiver component_type=splunk_hec_logs component_name=splunk_receiver}: vector::internal_events::splunk_hec::sink: Internal log [Timestamp was an unexpected type. Deferring to Splunk to set the timestamp.] is being rate limited.