Switch manifest for LineageOS Redvelvetcake

Patching

Basic:

Repopick topics icosa-bt-r, nvidia-shieldtech-r, nvidia-beyonder-r, and nvidia-nvgpu-r off Lineage Gerrit
Repopick commits 308972 and 304329 off Lineage Gerrit
Apply all patches to their respective directories (from patches folder)

Products

icosa_sr: Standard tablet Android with Nvidia enhancements, based on LineageOS
icosa_tv_sr: Android TV with Nvidia enhancements, based on LineageOS

Notes

In progress--may not boot