GUP: Add a global property for genreal preference

This change also fixes typos and adds some missing comments

Bug: 119221883
Test: Build, flash and boot, verify with prototype
Change-Id: Ida976c4fb3d4af5ffc1d9b977f00fa9c7239a434
Merged-In: Ida976c4fb3d4af5ffc1d9b977f00fa9c7239a434
6 files changed