I am using Android Studio 2.2 Preview. I am facing the issue
Failure: Install failed invalid apk Error: While installing apk,
Failure: Install failed invalid apk
Error: While installing apk,
Oh my goodness, after a long time I have resolved the issue by changing the ApplicationID: "com.company.2016app" to "com.company.app" in build.grade. It resolved all my issues. Now its working great.