[Auth] Add missing field to firebase claim in token result (#6234)

* Add missing field to firebase claim in token result

* Changeset.

* Update changeset from PR feedback

* Rebase

Author: sam-gc

.changeset/cool-elephants-leave.md

@@ -0,0 +1,5 @@
+---
+"@firebase/auth": patch
+---
+
+Add missing field to `firebase` claim in token result typing

common/api-review/auth.api.md

@@ -544,6 +544,7 @@ export interface ParsedToken {
     'firebase'?: {
         'sign_in_provider'?: string;
         'sign_in_second_factor'?: string;
+        'identities'?: Record<string, string>;
     };
     'iat'?: string;
     'sub'?: string;

packages/auth/src/model/public_types.ts

@@ -101,6 +101,7 @@ export interface ParsedToken {
   'firebase'?: {
     'sign_in_provider'?: string;
     'sign_in_second_factor'?: string;
+    'identities'?: Record<string, string>;
   };
   /** Map of any additional custom claims. */
   [key: string]: string | object | undefined;