You cannot trust Android phones. A lot of them have malware or are bound to get it (play store is riddled with them). Huawei phones (with Android) are rumoured to be in direct connection with the Chinese government, should they want to hear what you've got to say.
I will look into this i just got a galaxy alpha nice phone and was thinking of storing some coin on there because needs my finger print to get on so thought it would be safe i am starting to see it probably is not lol although it is new with no downloads so i might risk it with a coin or 2 think all the people that do and we don't hear these horror storys much do we. Sorry to hear about your loss buddy is there anything you have downloaded that you think might be the culprit?