Now I have solved my problem and found the culprit.
I tried every possible way to find the app that is causing unnecessary battery drain. Here is how I found the culprit.
On 24th July, I restarted my phone before sleeping and unlocked the owner profile but not user profile to see if user profile causing the problem. In morning, around 8hrs of duration my phone still lost 5% battery which is still high.
On 25th, I installed all sandboxed play services in owner profile. And only play services was on unrestricted battery. And i didn't restart the device. My battery drain was 3% in the duration of 8hrs.
On 26th, I deleted my user profile and installed all the apps in owner profile (because now there is no sense to keep using user profile because my main motive to use the user profile was separating play services app). But there was a surprise waiting for me. My battery drain was 9% for the duration of 8hrs(I will tell the culprit in the conclusion).
On 27th, I didn't change anything. Same setup as 26th. And idle battle drain was only 2% which is quite impressive considering 4410 mah battery.
On 28th, same setup as 27th. But this time I got update. And after update battery life got improved so much. It took only 1% of my battery in the night 8hrs.
And finally, on 29th, same setup as previous one. But this I turned on "Lift to check phone" to test how much this gesture consume battery (I was not using any gesture before). Idle battery drain was very good it was only 2%.
Here is the name of culprit is - "Media Server"
Because whenever battery drain was high, this service was in the top 4 of battery usage. And whenever phone had low battery drain this was absent in battery usage section. As muhomorr suggested some system service is keeping media playback awake.
I think by installing play services this issue has been solved, only one time this media server drained the battery on 26th july even after the presence of play services. So, user profile was not causing the problem. Final conclusion is Play Services are necessary evil. I wish there was open source alternative of play service just to get the notification.