SystemUI: Clock position customization

Co-authored-by: Hendrik Hagendorn <git@finnq.de>
Co-authored-by: kxxt <rsworktech@outlook.com>
Co-authored-by: LuK1337 <priv.luk@gmail.com>
Co-authored-by: Michael W <baddaemon87@gmail.com>
Co-authored-by: Pranav Vashi <neobuddy89@gmail.com>
Co-authored-by: Volodymyr Zhdanov <wight554@gmail.com>
Co-authored-by: kxxt <rsworktech@outlook.com>
Change-Id: Icdc039d13fd2676c1eb979a81fb77f9a6ec59b4a