Force hardware acceleration on Android

I tried modifying the Manifesto file by adding the line where I set the hardware acceleration to "true" (was following some steps), I built my app but no performance improvement.
I would like anyone skilled to tell me that using Unity 2017.1, how can one force hardware acceleration?

 

I am not the most skilled person, but isn't hardware acceleration a developer option? not sure if applications have access to that.

 

Sorry for the sloppy composition, dev options are at game too.
Where can I set that?

 

Its entirely possible that your app is built in such a way that hardware acceleration makes no difference.

Depending on where your performance is bottlenecking, this could be why you don't see a difference.

 

It's quite a simple app, runs smooth when no post-processing is applied, but starts to stutter (on weak, cheap devices) when post-processing is applied. I'm using Unity's post-processing stack.
I thought I could ease up on this by using HW acceleration.