I figured out the reason was - I had upgraded my phone and android studio during the days. If you are targetting sdk version 23 It will not show which permissions are required at the time of installation. And permissions had to be checked at run time if not available then you should write code to ask for permission.
If you don't want to do implement the new system yet then you can reduce your target sdk version to 22 to get the old permission system. You can still compile with sdk version 23 though.
See the documentation for more information.
I changed build.gradle (module app) settings to target sdk version from 23 to 22
And the app mentions the permission at the time of installation and runs file.
Let me know if this helped. you. Happy coding! :)