Android Activity is not working when installed by installer and click open button~

This is a strange
it happend from android OS version 1 from now on.
i'don't know why google dosen't fix it

anyway

it has a solution below

when called onCreate() in FirstActivity

check

if(!isTaskRoot()){
  finish();
  return;
}

I tested many time it working well.

and i hope it has no side effect.