Bump google.golang.org/grpc in /example/prom-collector (#1915)

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.37.0 to 1.37.1.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.37.0...v1.37.1)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>

example/prom-collector/go.mod

@@ -16,7 +16,7 @@ require (
 	go.opentelemetry.io/otel/metric v0.20.0
 	go.opentelemetry.io/otel/sdk v0.20.0
 	go.opentelemetry.io/otel/sdk/metric v0.20.0
-	google.golang.org/grpc v1.37.0
+	google.golang.org/grpc v1.37.1
 )
 
 replace go.opentelemetry.io/otel/bridge/opencensus => ../../bridge/opencensus

example/prom-collector/go.sum

@@ -412,8 +412,9 @@ google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQ
 google.golang.org/grpc v1.26.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.27.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.33.1/go.mod h1:fr5YgcSWrqhRRxogOsw7RzIpsmvOZ6IcH4kBYTpR3n0=
-google.golang.org/grpc v1.37.0 h1:uSZWeQJX5j11bIQ4AJoj+McDBo29cY1MCoC1wO3ts+c=
 google.golang.org/grpc v1.37.0/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQdJfM=
+google.golang.org/grpc v1.37.1 h1:ARnQJNWxGyYJpdf/JXscNlQr/uv607ZPU9Z7ogHi+iI=
+google.golang.org/grpc v1.37.1/go.mod h1:NREThFqKR1f3iQ6oBuvc5LadQuXVGo9rkm5ZGrQdJfM=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=