yaap/kernel_oneplus_sm8650 ? reverse-engineered prompt

Build me a working Android kernel project for a OnePlus phone using this source tree.

I want a clean setup that can be built for the supported device variants in this repo, and I want the usual Android kernel build files and instructions to work without breaking the common kernel configs. If there are any missing build steps, scripts, or docs needed to make it easier to compile and package the kernel image, add them.

Please keep it aligned with Android common kernel rules, so it still builds with the standard kernel configs and follows the patch and sign off requirements in the README. If you need current kernel or Android build docs to verify anything, look them up online.

Make the repo easier to use for someone who just wants to build the kernel, test it, and submit changes correctly.