remove last use of setPort/setServiceAddress

Fixes #1835.

Author: pongad

google-cloud-core/src/main/java/com/google/cloud/GrpcTransportOptions.java

@@ -215,8 +215,7 @@ public UnaryCallSettings.Builder getApiCallSettings(RetrySettings retrySettings)
   public static ChannelProvider setUpChannelProvider(
       InstantiatingChannelProvider.Builder providerBuilder, ServiceOptions<?, ?> serviceOptions) {
     HostAndPort hostAndPort = HostAndPort.fromString(serviceOptions.getHost());
-    providerBuilder.setServiceAddress(hostAndPort.getHostText())
-        .setPort(hostAndPort.getPort())
+    providerBuilder.setEndpoint(hostAndPort.getHostText() + ':' + hostAndPort.getPort())
         .setClientLibHeader(ServiceOptions.getGoogApiClientLibName(),
             firstNonNull(ServiceOptions.getLibraryVersion(), ""));
     Credentials scopedCredentials = serviceOptions.getScopedCredentials();