fallout of splitting rect.h out of libandroid.

A lot of media makefiles didn’t specify libui or
libgui but included headers from these libraries
directly. 

It works because these headers are on the global
include path. With this change, though, rect.h
is not anymore (albeit exported from libui).

Test: built and booted device
Bug: 35164655
Change-Id: I72e8f0b7bd25c6a67eedc17afe52c4c484a147fe