Android app downloading but not installing

My Device is Motorola Moto G 1st Gen. running Android Lollipop 5.0.2 From the last 2-3 months, my phone is not installing apps. It downloads the app and even shows installing but never completes. After showing "Installing " for some time, the notification will go. If I go back to Play Store, it says "Install" and not Installing. So I have to repeat the same procedure. I have tried clearing Data and Cache of Play Store, Download Manager, Google Play Services. I have over 5 GB space available on phone. I have tried the above solution many times but it doesn't works. The only thing I don't want to do is factory reset. Update: After I updated to Android 5.1, apps started to install properly so I think it was a bug related to 5.0.2