it is true no possible mining on the phone ?
Still possible, but not worth at all. For mining bitcoin in android smartphone you need minimum smartphone with 8-cores processor and it need about 100-200 unit. It takes much cost to buy 200 smartphones with 8-cores, in addition there is an other cost, such as electricity and internet access for 1 year. While the results of your mining for 1 year is only 2% comparing with of the total cost that you already spent, it is not worth it all.
Because with those price, you can buy few special hardware equipment special to work mined bitcoin such as antminer , this option is much better.