You have to support only 6 pretty much, which comes quite close to how many you have to support on iOS right now (you mentioned 5):
ldpi (low) ~120dpi
mdpi (medium) ~160dpi
hdpi (high) ~240dpi
xhdpi (extra-high) ~320dpi
xxhdpi (extra-extra-high) ~480dpi
xxxhdpi (extra-extra-extra-high) ~640dpi
https://developer.android.com/guide/practices/screens_suppor...