How do I Optimize Resources/Unity_Builtin_Extra

I’m relatively new to unity and I’ve been working on a small Android game. As I’ve worked on it however, I noticed the size has been visibly increasing. Following information on how to figure out what’s taking up the most space. As a result I did find some things like textures I forgot to resize but first and foremost this showed up:

45.9 mb	 58.9% Resources/unity_builtin_extra

Furthermore:

Textures      18.7 mb	 24.0% 
Meshes        3.8 mb	 4.8% 
Animations    0.0 kb	 0.0% 
Sounds        0.0 kb	 0.0% 
Shaders       46.0 mb	 59.0% 
Other Assets  627.4 kb	 0.8% 
Levels        4.1 mb	 5.3% 
Scripts       601.0 kb	 0.8% 
Included DLLs 4.1 mb	 5.2% 
File headers  105.9 kb	 0.1% 
Complete size 78.0 mb	 100.0% 

Judging from this information I would assume that I have some sort of amazingly large shader that’s bloating the size of my game and that shader is related to unity_builtin_extra but I have no clue how I’m supposed to hunt it down and change/remove it. I’ve tried to looked around for information but none of the ones I discovered have been answered.

I later found that Resources/unity_builtin_extra seemed to refer to the entire standard asset folder. In general I went around cleaning basic unity assets that I imported but didn’t use and that decreased the size by a significant amount and thus solving my problem.