android/base/System.h: Add addLibrarySearchDir().

Add a new method to modify the runtime library search path.

This really moves a little bit of code from emugl_config.cpp
into a more generic location. The new method will also be used
in a future patch to adjust the search path to find the Qt shared
libraries, which will be stored under $OUT_DIR/<lib>/qt/

Change-Id: I029e91eeb6a960e4340bda5345c9e375b11b16f4
6 files changed