[BUG] Nearby Riders snackbars are buggy

[urmilshroff]

Describe the bug
Snackbar is displayed with random, incorrect info at times.

To reproduce
Steps to reproduce the behavior:

1. Launch the app and swipe to mark location
2. Snackbar will show n nearby Riders
3. It will randomly update with n+1 or n-1 nearby Riders
4. Then it will change again

Expected behavior
Snackbar should be displayed with correct info only when the number of nearby Riders actually change