Pass device characteristic information through to aapt.

A build configuration can define PRODUCT_CHARACTERISTICS, which is
a comma-separated list of device characteristics, for example
"nosdcard,grayscale".  This will be passed through to aapt with
the --product flag.

Change-Id: I902c034b2f2824dbd2d33449308ee08beeb09551
diff --git a/core/product_config.mk b/core/product_config.mk
index 4824245..70ac894 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -253,6 +253,12 @@
   PRODUCT_MANUFACTURER := unknown
 endif
 
+ifeq ($(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_CHARACTERISTICS),)
+  TARGET_AAPT_CHARACTERISTICS := default
+else
+  TARGET_AAPT_CHARACTERISTICS := $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_CHARACTERISTICS))
+endif
+
 PRODUCT_DEFAULT_WIFI_CHANNELS := \
 	$(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_DEFAULT_WIFI_CHANNELS))