Move Settings app to /product

Since this app is frequently customized by OEMs, it doesn't
fit in the mainline /system image right now. Move it to
/product.

Bug: 110072687
Test: make
Change-Id: Iee5940125af3f2a8543ecb3a68d7fba737acd77d
Merged-In: Iee5940125af3f2a8543ecb3a68d7fba737acd77d
(cherry picked from commit f109282c)