exporter/{metric,trace}: fix README.md example to latest API (#612)

Signed-off-by: Koichi Shiraishi <zchee.io@gmail.com>

Author: zchee

exporter/metric/README.md

@@ -19,8 +19,10 @@ After you import the metric exporter package, then register the exporter to the
 package main
 
 import (
+	"context"
+	"log"
+
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/sdk/metric"
 
 	mexporter "github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/metric"
@@ -41,14 +43,14 @@ func main() {
 	// Start meter
 	meter := provider.Meter("github.com/GoogleCloudPlatform/opentelemetry-operations-go/example/metric")
 
-	counter, err := meter.SyncInt64().Counter("counter-foo")
+	counter, err := meter.Int64Counter("counter-foo")
 	if err != nil {
 		log.Fatalf("Failed to create counter: %v", err)
 	}
-	labels := []label.KeyValue{
-		label.Key("key").String("value"),
+	attrs := []attribute.KeyValue{
+		attribute.Key("key").String("value"),
 	}
-	counter.Add(ctx, 123, labels...)
+	counter.Add(ctx, 123, attrs...)
 }
 ```
 

exporter/trace/README.md

@@ -59,13 +59,8 @@ When running code locally, you may need to specify a Google Project ID in additi
 
 ```go
 projectID := os.Getenv("GOOGLE_CLOUD_PROJECT")
-_, shutdown, err := texporter.InstallNewPipeline(
-    []texporter.Option {
-        texporter.WithProjectID(projectID),
-        // other optional exporter options
-    },
-    ...
-)
+exporter, err := texporter.New(texporter.WithProjectID(projectID))
+...
 ```
 
 ## Useful links