[android] Fix climbing snackbar

Use a fresh snackbar for pending contacts each time it needs to be
shown. Don't re-use the old instance and clear it in onStop().
1 job for 1582-fix-climbing-snackbar in 13 minutes and 51 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Test
passed #4685
test

00:13:51