It is because you are running it as a ‘test’ and not as an ‘Android Application’.
- Open the “Edit Configurations” pane and click the ‘+’ button.
- Select the option to create a new ‘Android Application’ and then select the correct module.
- Apply, and you can then delete the test configuration you were using before if you wish.
Then every time you run, make sure you are running as an Android Application and not a test, and it will auto-launch on install.