Retry more Google API failures.

The default retry policy (documented
[here](https://github.com/googleapis/gaxios/#request-options)) does not
retry POST requests. But most Google API calls use POST requests under
the covers, including read-only APIs like [Drive
Activity](https://developers.google.com/drive/activity/v2/reference/rest/v2/activity/query).
So we can also ask to retry POST requests.

We retain other aspects of the default policy, such as the number of
attempts (3) and the HTTP status codes to retry (100-109, 408, 429,
5xx). If a request succeeds on a retry, the failure is kept silent and
does not pollute the logs.

The main risk is that a POST method might mutate some state despite
returning a failure, and that inline retries might handle that
incorrectly or otherwise make things worse than retrying the full flow
from the ground up. This doesn't seem likely to be an issue with the
current set of API calls, but if desired, we could narrow this change to
specific known-safe requests.

See deathandmayhem#2160
See deathandmayhem#2161

imports/server/googleClientRefresher.ts

@@ -10,6 +10,7 @@ import type { people_v1 } from "@googleapis/people";
 import { people } from "@googleapis/people";
 import type { script_v1 } from "@googleapis/script";
 import { script } from "@googleapis/script";
+import type { RetryConfig } from "gaxios";
 import type { SettingType } from "../lib/models/Settings";
 import Settings from "../lib/models/Settings";
 
@@ -32,12 +33,19 @@ class GoogleClientRefresher {
 
   private oauthCredentialCursor: Mongo.Cursor<SettingType>;
 
+  private retryConfig: RetryConfig;
+
   constructor() {
     this.drive = undefined;
     this.oauthClient = undefined;
     this.oauthConfig = undefined;
     this.oauthRefreshToken = undefined;
 
+    this.retryConfig = {
+      // Retry POST failures as well, since most APIs use POST requests under the covers.
+      httpMethodsToRetry: ["GET", "PUT", "HEAD", "OPTIONS", "DELETE", "POST"],
+    };
+
     // Watch for config changes, and refresh the gdrive instance if anything changes
     this.oauthConfigCursor = ServiceConfiguration.configurations.find({
       service: "google",
@@ -97,13 +105,26 @@ class GoogleClientRefresher {
     });
 
     // Construct the clients, using that OAuth2 client.
-    this.drive = drive({ version: "v3", auth: this.oauthClient });
+    this.drive = drive({
+      version: "v3",
+      auth: this.oauthClient,
+      retryConfig: this.retryConfig,
+    });
     this.driveactivity = driveactivity({
       version: "v2",
       auth: this.oauthClient,
+      retryConfig: this.retryConfig,
+    });
+    this.script = script({
+      version: "v1",
+      auth: this.oauthClient,
+      retryConfig: this.retryConfig,
+    });
+    this.people = people({
+      version: "v1",
+      auth: this.oauthClient,
+      retryConfig: this.retryConfig,
     });
-    this.script = script({ version: "v1", auth: this.oauthClient });
-    this.people = people({ version: "v1", auth: this.oauthClient });
   }
 }