Add support for loading layers from the apk.

Added the vulkan_layer_path interface which is used to set the path from
ThreadedRenderer. The vulkan loader then uses this path to search for layer
libraries that come preinstalled with the app.

Change-Id: Iee7d56c1950296ba5ece3a119741406d705479a8
(cherry picked from commit 1f920c1e52bbd59405761e5403def5dbc22e331b)
diff --git a/vulkan/libvulkan/Android.mk b/vulkan/libvulkan/Android.mk
index bcb1e8b..7a2eb64 100644
--- a/vulkan/libvulkan/Android.mk
+++ b/vulkan/libvulkan/Android.mk
@@ -33,7 +33,8 @@
 	entry.cpp \
 	get_proc_addr.cpp \
 	loader.cpp \
-	swapchain.cpp
+	swapchain.cpp \
+	vulkan_loader_data.cpp
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 
 LOCAL_SHARED_LIBRARIES := libhardware liblog libsync libcutils