Add soong variable for PRODUCT_FULL_TREBLE.

Required to preserve sane defaults for old codebases.

Test: inspect soong.variables
Test: ensure PRODUCT_SHIPPING_API_LEVEL is set in config.mk
Bug: 38415912
Change-Id: I0244fb02754663be3106391c9360fd1b2cc00d4a
diff --git a/core/config.mk b/core/config.mk
index badb9b1..d12150e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -689,6 +689,16 @@
 APICHECK_CLASSPATH := $(APICHECK_CLASSPATH):$(HOST_OUT_JAVA_LIBRARIES)/jsilver$(COMMON_JAVA_PACKAGE_SUFFIX)
 APICHECK_COMMAND := $(APICHECK) -JXmx1024m -J"classpath $(APICHECK_CLASSPATH)"
 
+# Boolean variable determining if Treble is fully enabled
+PRODUCT_FULL_TREBLE := false
+ifneq ($(PRODUCT_FULL_TREBLE_OVERRIDE),)
+  PRODUCT_FULL_TREBLE := $(PRODUCT_FULL_TREBLE_OVERRIDE)
+else ifeq ($(PRODUCT_SHIPPING_API_LEVEL),)
+  #$(warning no product shipping level defined)
+else ifneq ($(call math_gt_or_eq,$(PRODUCT_SHIPPING_API_LEVEL),26),)
+  PRODUCT_FULL_TREBLE := true
+endif
+
 # The default key if not set as LOCAL_CERTIFICATE
 ifdef PRODUCT_DEFAULT_DEV_CERTIFICATE
   DEFAULT_SYSTEM_DEV_CERTIFICATE := $(PRODUCT_DEFAULT_DEV_CERTIFICATE)
diff --git a/core/main.mk b/core/main.mk
index f22e63d..0bb887c 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -187,16 +187,6 @@
   ADDITIONAL_BUILD_PROPERTIES += ro.bionic.ld.warning=1
 endif
 
-# Boolean variable determining if Treble is fully enabled
-PRODUCT_FULL_TREBLE := false
-ifneq ($(PRODUCT_FULL_TREBLE_OVERRIDE),)
-  PRODUCT_FULL_TREBLE := $(PRODUCT_FULL_TREBLE_OVERRIDE)
-else ifeq ($(PRODUCT_SHIPPING_API_LEVEL),)
-  #$(warning no product shipping level defined)
-else ifneq ($(call math_gt_or_eq,$(PRODUCT_SHIPPING_API_LEVEL),26),)
-  PRODUCT_FULL_TREBLE := true
-endif
-
 # -----------------------------------------------------------------
 ###
 ### In this section we set up the things that are different
diff --git a/core/soong_config.mk b/core/soong_config.mk
index 0a2208b..977b35c 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -80,6 +80,7 @@
 	echo '    "EnableCFI": $(if $(filter false,$(ENABLE_CFI)),false,true),'; \
 	echo '    "Device_uses_hwc2": $(if $(filter true,$(TARGET_USES_HWC2)),true,false),'; \
 	echo '    "Override_rs_driver": "$(OVERRIDE_RS_DRIVER)",'; \
+	echo '    "Treble": $(if $(filter true,$(PRODUCT_FULL_TREBLE)),true,false),'; \
 	echo ''; \
 	echo '    "ArtUseReadBarrier": $(if $(filter false,$(PRODUCT_ART_USE_READ_BARRIER)),false,true),'; \
 	echo ''; \