解决方法
Firebase开发人员在他们的论坛上有
this to say：
I would not rely on a constant length for the UIDs forever. We chose the current value because it provides a big enough ID space while still being under the 36-character limit for Firebase Analytics user properties.
所以,换句话说,你所建议的将来可能会或可能不会失败,所以你可能应该找到一种不同的实现方式,这种方式更具有前瞻性.
