Limit gRPC's built-in exponential backoff (#1390)

* Prevent gRPC from performing too much exponential backoff

* [AUTOMATED]: Prettier Code Styling

* Simplify comment

* Set the initial backoff as low as possible

* revert testing change

Author: ryanpbrewster

packages/firestore/src/platform_node/grpc_connection.ts

@@ -113,7 +113,17 @@ export class GrpcConnection implements Connection {
         ? grpc.credentials.createSsl()
         : grpc.credentials.createInsecure();
       this.cachedStub = {
-        stub: new this.firestore.Firestore(this.databaseInfo.host, credentials),
+        stub: new this.firestore.Firestore(
+          this.databaseInfo.host,
+          credentials,
+          {
+            // We do our own connection backoff (that for example is aware of whether or
+            // not a write stream error is permanent or not) so we don't want gRPC to do
+            // backoff on top of that. 100ms is the minimum value that gRPC allows.
+            'grpc.initial_reconnect_backoff_ms': 100,
+            'grpc.max_reconnect_backoff_ms': 100
+          }
+        ),
         token
       };
     }