enable developer options visibility by default for userdebug builds

Signed-off-by: Roman Birg <romanbirg@gmail.com>
Settings: Removed system update option

Removed system update from Settings>About phone

Change-Id: If3aab16b6877736dadafdac0a2cd46afe56d80f7
Signed-off-by: Arham Jamal <arhamjamal@gmail.com>