What's the difference between Android SDK Update Sites `https://dl.google.com/android/repository/repository2-1.xml` and `2-2.xml`?

In my Android Studio, it given two default SDK Update sites:

https://dl.google.com/android/repository/repository2-1.xml
https://dl.google.com/android/repository/repository2-2.xml

I use code compare tool to contrast them, then I found only several differences:

1.

2. checksum property added type="sha1"

3.

from What's the difference between Android SDK Update Sites `https://dl.google.com/android/repository/repository2-1.xml` and `2-2.xml`?