during Fajr salah i noticed that some people read 2 rakaats before azaan. they continue to read the quraan thereafter. after the muazzin completes the azaan, they continue to read the quraan sharief. they only stand up to read the fardh namaaz behind the imam. question is – is it permissible to read the 2 sunnats of fajr salah before the azaan in the masjid?