fastscroller in groups activity and center activity

[sats98]

Summary: The group list and center list can`t be scrolled fast. It takes much time to keep scrolling down. Therefore add fastscroller.

Steps to reproduce:

1- Open the navigation bar. 2- Go to Groups or Centers. 3- The list doesn`t contain fastscroller.

Expected behaviour:

Observed behaviour:

The person has to scroll a lot to reach the end of list. The complexity increases as the list increases.

Device and Android version:

Xiaomi Redmi Note 4 (Android 7.0, API 24)

[sats98]

i have done that but not able to push showing Travis CI build failed?