CMakelists generator: Maintain include order

For some library, the order of includes is important. e.g: library
can include "system/window.h". Dependending on the dependency order
this could mean libs/nativewindow/include/system/window.h or
system/core/include/system/window.h

This patch changes search path storage from map to array in order
to preserve order the order in which they were received from
soong.

Change-Id: I8ef788633985f4ed04ec3432686eb1427f73d600
Test: Manual