I have seen this too. LookingLooking thru the code, it appears that the pager templates do have translations set up properly. SoSo in theory, UI translations should work. ButBut they don't.
I haven't tried it but you probably could do this thru the hook_preprocess_pager__page(&$variables)hook_preprocess_pager__page(&$variables)
function (for full views pages). There seems to be a $variables['pager']['#tags']$variables['pager']['#tags']
array with the values for pagers. YouYou might be able to do the UI string translation here.