fix: remove default global trace context propagator (#2209)

Fixes #2208

Author: surbhigarg92

src/index.ts

@@ -85,7 +85,6 @@ import * as v1 from './v1';
 import {
   ObservabilityOptions,
   ensureInitialContextManagerSet,
-  ensureContextPropagation,
 } from './instrument';
 
 // eslint-disable-next-line @typescript-eslint/no-var-requires
@@ -378,7 +377,6 @@ class Spanner extends GrpcService {
       this._observabilityOptions?.enableEndToEndTracing
     );
     ensureInitialContextManagerSet();
-    ensureContextPropagation();
   }
 
   /**

src/instrument.ts

@@ -27,7 +27,6 @@ import {
   Span,
   SpanStatusCode,
   context,
-  propagation,
   trace,
   INVALID_SPAN_CONTEXT,
   ROOT_CONTEXT,
@@ -100,8 +99,6 @@ const {
   AsyncHooksContextManager,
 } = require('@opentelemetry/context-async-hooks');
 
-const {W3CTraceContextPropagator} = require('@opentelemetry/core');
-
 /*
  * This function ensures that async/await works correctly by
  * checking if context.active() returns an invalid/unset context
@@ -121,14 +118,8 @@ function ensureInitialContextManagerSet() {
   }
 }
 
-function ensureContextPropagation() {
-  propagation.setGlobalPropagator(new W3CTraceContextPropagator());
-}
-
 export {ensureInitialContextManagerSet};
 
-export {ensureContextPropagation};
-
 /**
  * startTrace begins an active span in the current active context
  * and passes it back to the set callback function. Each span will