fix: ApiKeyCredentials is passed to CallOptions

Author: lqiu96

gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcCallContext.java

@@ -47,6 +47,7 @@
 import com.google.api.gax.rpc.internal.Headers;
 import com.google.api.gax.tracing.ApiTracer;
 import com.google.api.gax.tracing.BaseApiTracer;
+import com.google.auth.ApiKeyCredentials;
 import com.google.auth.Credentials;
 import com.google.auth.Retryable;
 import com.google.common.base.Preconditions;
@@ -192,7 +193,9 @@ public GrpcCallContext nullToSelf(ApiCallContext inputContext) {
  public GrpcCallContext withCredentials(Credentials newCredentials) {
  Preconditions.checkNotNull(newCredentials);
  CallOptions newCallOptions = callOptions;
- if (channelCredentials == null || !(channelCredentials == newCredentials)) {
+ if (channelCredentials == null
+ || newCredentials instanceof ApiKeyCredentials
+ || !(channelCredentials == newCredentials)) {
  newCallOptions = callOptions.withCallCredentials(MoreCallCredentials.from(newCredentials));
  }
  return new GrpcCallContext(