Add PRODUCT_DEFAULT_WIFI_CHANNELS build var.

Allows the build to specify the default number of allowed
WIFI channels.  Part of the fix for 1625953.

core/Makefile

@@ -118,6 +118,7 @@ $(INSTALLED_BUILD_PROP_TARGET): $(BUILDINFO_SH) $(INTERNAL_BUILD_ID_MAKEFILE)
 			PRODUCT_BRAND="$(PRODUCT_BRAND)" \
 			PRODUCT_DEFAULT_LANGUAGE="$(call default-locale-language,$(PRODUCT_LOCALES))" \
 			PRODUCT_DEFAULT_REGION="$(call default-locale-region,$(PRODUCT_LOCALES))" \
+			PRODUCT_DEFAULT_WIFI_CHANNELS="$(PRODUCT_DEFAULT_WIFI_CHANNELS)" \
 			PRODUCT_MODEL="$(PRODUCT_MODEL)" \
 			PRODUCT_MANUFACTURER="$(PRODUCT_MANUFACTURER)" \
 			PRIVATE_BUILD_DESC="$(PRIVATE_BUILD_DESC)" \

core/product.mk

@@ -68,7 +68,8 @@ _product_var_list := \
     PRODUCT_SDK_ADDON_NAME \
     PRODUCT_SDK_ADDON_COPY_FILES \
     PRODUCT_SDK_ADDON_COPY_MODULES \
-    PRODUCT_SDK_ADDON_DOC_MODULE
+    PRODUCT_SDK_ADDON_DOC_MODULE \
+    PRODUCT_DEFAULT_WIFI_CHANNELS
 
 define dump-product
 $(info ==== $(1) ====)\

core/product_config.mk

@@ -214,6 +214,9 @@ ifndef PRODUCT_MANUFACTURER
   PRODUCT_MANUFACTURER := unknown
 endif
 
+PRODUCT_DEFAULT_WIFI_CHANNELS := \
+	$(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_DEFAULT_WIFI_CHANNELS))
+
 # Which policy should this product use
 PRODUCT_POLICY := $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_POLICY))