fireMessaging.tokenChanges emit wrong(not equeal) fcm token after fireMessaging.requestToken

### Version info

**Angular:*17.3.3*

**Firebase:*-*

**AngularFire:*17.1.0*

**Other (e.g. Ionic/Cordova, Node, browser, operating system):*browser*

### How to reproduce these conditions
1) Create subscription on fireMessaging.tokenChanges, can be several
2) Run fireMessaging.requestToken
3) Compare fcm token from tokenChanges & requestToken

Currently, we have different results, also each new subscription generates a new fcm token + additional HTTP requests

### Expected behavior

Same fcm tokens + only required numbers of HTTP requests

### Actual behavior

Different fcm tokens

首先，透過 issue 中描述的 fireMessaging.tokenChanges 訂閱和 fireMessaging.requestToken 呼叫重現此行為，並比較發出的 token 和 HTTP 要求。完成的條件是，重複訂閱和明確要求只發出必要的要求，並產生相同的 FCM token。

由索引模型根據 Issue 內容生成。