Use 'inherit-product/inherit-product-if-exists to include config files

Bug: 172923994
Test: treehugger
Change-Id: I762dfa8dc48c0b09597d2f7b6ef7f53062915a79
diff --git a/target/product/generic_x86.mk b/target/product/generic_x86.mk
index 0274b5b..eeb8216 100644
--- a/target/product/generic_x86.mk
+++ b/target/product/generic_x86.mk
@@ -17,7 +17,7 @@
 # This is a generic phone product that isn't specialized for a specific device.
 # It includes the base Android platform.
 
-include $(SRC_TARGET_DIR)/product/generic.mk
+$(call inherit-product, $(SRC_TARGET_DIR)/product/generic.mk)
 
 # Overrides
 PRODUCT_BRAND := generic_x86
diff --git a/target/product/sdk_phone_x86.mk b/target/product/sdk_phone_x86.mk
index 63671dc..9096ff3 100644
--- a/target/product/sdk_phone_x86.mk
+++ b/target/product/sdk_phone_x86.mk
@@ -50,8 +50,8 @@
 $(call inherit-product, $(SRC_TARGET_DIR)/board/emulator_x86/device.mk)
 
 # Define the host tools and libs that are parts of the SDK.
--include sdk/build/product_sdk.mk
--include development/build/product_sdk.mk
+$(call inherit-product-if-exists, sdk/build/product_sdk.mk)
+$(call inherit-product-if-exists, development/build/product_sdk.mk)
 
 # Overrides
 PRODUCT_BRAND := Android
diff --git a/target/product/sdk_phone_x86_64.mk b/target/product/sdk_phone_x86_64.mk
index c5a6245..161043b 100644
--- a/target/product/sdk_phone_x86_64.mk
+++ b/target/product/sdk_phone_x86_64.mk
@@ -51,8 +51,8 @@
 $(call inherit-product, $(SRC_TARGET_DIR)/board/emulator_x86_64/device.mk)
 
 # Define the host tools and libs that are parts of the SDK.
--include sdk/build/product_sdk.mk
--include development/build/product_sdk.mk
+$(call inherit-product-if-exists, sdk/build/product_sdk.mk)
+$(call inherit-product-if-exists, development/build/product_sdk.mk)
 
 # Overrides
 PRODUCT_BRAND := Android