fix: explicitly set quota user in Service Usage API calls. (#8768)

* fix: explicitly set quota user in Service Usage API calls.

* fix: support overriding quotta project on polling requests

---------

Co-authored-by: joehan <joehanley@google.com>

Author: taeold

src/gcp/serviceusage.ts

@@ -34,6 +34,8 @@ export async function generateServiceIdentity(
   try {
     const res = await apiClient.post<unknown, unknown>(
       `projects/${projectNumber}/services/${service}:generateServiceIdentity`,
+      /* body=*/ {},
+      { headers: { "x-goog-quota-user": `projects/${projectNumber}` } },
     );
     return res.body as LongRunningOperation<unknown>;
   } catch (err: unknown) {
@@ -65,5 +67,6 @@ export async function generateServiceIdentityAndPoll(
   await poller.pollOperation<void>({
     ...serviceUsagePollerOptions,
     operationResourceName: op.name,
+    headers: { "x-goog-quota-user": `projects/${projectNumber}` },
   });
 }

src/operation-poller.ts

@@ -23,6 +23,7 @@ export interface OperationPollerOptions {
   masterTimeout?: number;
   onPoll?: (operation: OperationResult<any>) => any;
   doneFn?: (op: any) => boolean;
+  headers?: Record<string, string>;
 }
 
 const DEFAULT_INITIAL_BACKOFF_DELAY_MILLIS = 250;
@@ -80,7 +81,9 @@ export class OperationPoller<T> {
     return async () => {
       let res;
       try {
-        res = await apiClient.get<OperationResult<T>>(options.operationResourceName);
+        res = await apiClient.get<OperationResult<T>>(options.operationResourceName, {
+          headers: options.headers,
+        });
       } catch (err: any) {
         // Responses with 500 or 503 status code are treated as retriable errors.
         if (err.status === 500 || err.status === 503) {