Drop LoadController to just rely on DefaultLoadControl of ExoPlayer

[Redirion]

What is it?

• Bug fix (user facing)
• Feature (user facing)
• Code base improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

In the future I would prefer to rely on Google to find reasonable values for buffers as they do in their DefaultLoadControl.
The last change to buffer values NewPipe did was 2,5 Years ago with this commit: b466836
The commit aimed to speed up start of initial playback.
However as issues like #3251 show, on an unstable connection, this can lead to buffer under-runs.
On the other hand I don't think that users with a high speed connection will notice this change as the high speed connection will fill the 5 times longer start buffer duration quick anyway. This is also the most significant change by dropping NewPipe's LoadController. The minimum buffer is increased from 500ms to 2500ms.

Fixes the following issue(s)

Fixes #3251

Testing apk

https://github.com/Redirion/NewPipe/releases/tag/removeloadcontroller

Agreement

• I carefully read the contribution guidelines and agree to them.

[opusforlife2]

@Redirion Doesn't this conflict with #4246?

[avently]

@Redirion if you want to change some default values why not to change them without removing LoadController? If you think it's reasonable choice