I am using Android Studio 2.2 Preview. I am facing the issue
Failure: Install failed invalid apk
Error: While installing apk,
In lollipop and above versions Android introduced multiple users, When you delete an app it still exists in device. Please make sure your app is deleted from all users and then reinstall it.
You can check by going to Settings->Apps->All and check your app in the list, On selecting your app tap on more button in actionbar and select uninstall for all users.