fix elixir trace_id/span_id types to reference the Erlang types

Author: tsloughter

apps/opentelemetry_api/lib/open_telemetry.ex

@@ -44,14 +44,14 @@ defmodule OpenTelemetry do
   the same `trace_id`. The ID is a 16-byte array. An ID with all zeroes
   is considered invalid.
   """
-  @type trace_id() :: non_neg_integer()
+  @type trace_id() :: :opentelemetry.trace_id()
 
   @typedoc """
   SpanId is a unique identifier for a span within a trace, assigned when the span
   is created. The ID is an 8-byte array. An ID with all zeroes is considered
   invalid.
   """
-  @type span_id() :: non_neg_integer()
+  @type span_id() :: :opentelemetry.span_id()
 
   @type attribute_key() :: :opentelemetry.attribute_key()
   @type attribute_value() :: :opentelemetry.attribute_value()