ENG-48179: Revert to use DialContext in grpc client

With NewClient API usage, we are facing issues at
few customers who have intermediate proxies between collector
and platform. With NewClient API instead Dial,
DNS resolution happens on the client side while it should happen on proxy.
Also, with SGProxy client does not get the correct certificate.
This can be changed once grpc fixes grpc/grpc-go#7556 and otel collector picks the fix

FORK.md

@@ -21,4 +21,5 @@ git push --tags
 - In `config/configgrpc/configgrpc.go` we added the ability to add extra `ClientDialOptionHandler`. Also a unit test for this in `config/configgrpc/configgrpcclientdialoptionhandler_test.go`. Also commented out warning on servers starting `UnspecifiedHost` aka `0.0.0.0`.
 - In `config/configgrpc/configgrpc_test.go` we commented a unit test checking for a warning on servers starting `UnspecifiedHost` aka `0.0.0.0`.
 - In `config/confighttp/confighttp.go` we commented out warning on servers starting `UnspecifiedHost`.
-- In ` config/confighttp/confighttp_test.go` we commented a unit test checking for a warning on servers starting `UnspecifiedHost`.
+- In `config/confighttp/confighttp_test.go` we commented a unit test checking for a warning on servers starting `UnspecifiedHost`.
+- In `config/configgrpc/configgrpc.go` we reverted back to use `grpc.DialContext` method instead of `grpc.NewClient`

config/configgrpc/configgrpc.go

@@ -224,13 +224,13 @@ func (gcs *ClientConfig) isSchemeHTTPS() bool {
 // a non-blocking dial (the function won't wait for connections to be
 // established, and connecting happens in the background). To make it a blocking
 // dial, use grpc.WithBlock() dial option.
-func (gcs *ClientConfig) ToClientConn(_ context.Context, host component.Host, settings component.TelemetrySettings, extraOpts ...grpc.DialOption) (*grpc.ClientConn, error) {
+func (gcs *ClientConfig) ToClientConn(ctx context.Context, host component.Host, settings component.TelemetrySettings, extraOpts ...grpc.DialOption) (*grpc.ClientConn, error) {
 	opts, err := gcs.toDialOptions(host, settings)
 	if err != nil {
 		return nil, err
 	}
 	opts = append(opts, extraOpts...)
-	return grpc.NewClient(gcs.sanitizedEndpoint(), opts...)
+	return grpc.DialContext(ctx, gcs.sanitizedEndpoint(), opts...) //nolint
 }
 
 func (gcs *ClientConfig) toDialOptions(host component.Host, settings component.TelemetrySettings) ([]grpc.DialOption, error) {