原来，旧的Crashlytics JAR仍隐藏在我的 libs $ c中$ c>文件夹，并将其删除后，此错误不再存在。

It turns out that the old Crashlytics JAR was still hiding in my libs folder somehow, and after removing it, this error no longer persists.

我有点头脑呆滞，但我会留用这笔钱来帮助将来的Google员工谁遇到了同样的问题。 ：）

I feel a little boneheaded, but I'll leave this up to help any future Googlers who run into the same issue. :)