Support for recovery snapshot.

Bug: 171231437
Test: source build/envsetup.sh
Test: ALLOW_MISSING_DEPENDENCIES=true m -j nothing
Change-Id: I6dbcf21ee26c53cd3ac573d118a99d68161aa2c7
diff --git a/core/soong_config.mk b/core/soong_config.mk
index ae494c4..c01681d 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -129,6 +129,7 @@
 $(call add_json_str,  ProductVndkVersion,                $(PRODUCT_PRODUCT_VNDK_VERSION))
 $(call add_json_list, ExtraVndkVersions,                 $(PRODUCT_EXTRA_VNDK_VERSIONS))
 $(call add_json_list, DeviceSystemSdkVersions,           $(BOARD_SYSTEMSDK_VERSIONS))
+$(call add_json_str,  RecoverySnapshotVersion,           $(RECOVERY_SNAPSHOT_VERSION))
 $(call add_json_list, Platform_systemsdk_versions,       $(PLATFORM_SYSTEMSDK_VERSIONS))
 $(call add_json_bool, Malloc_not_svelte,                 $(call invert_bool,$(filter true,$(MALLOC_SVELTE))))
 $(call add_json_bool, Malloc_zero_contents,              $(call invert_bool,$(filter false,$(MALLOC_ZERO_CONTENTS))))
diff --git a/core/tasks/recovery_snapshot.mk b/core/tasks/recovery_snapshot.mk
index fea0bb9..525273b 100644
--- a/core/tasks/recovery_snapshot.mk
+++ b/core/tasks/recovery_snapshot.mk
@@ -14,21 +14,21 @@
 
 current_makefile := $(lastword $(MAKEFILE_LIST))
 
-# BOARD_VNDK_VERSION must be set to 'current' in order to generate a recovery snapshot.
-ifeq ($(BOARD_VNDK_VERSION),current)
+# RECOVERY_SNAPSHOT_VERSION must be set to 'current' in order to generate a recovery snapshot.
+ifeq ($(RECOVERY_SNAPSHOT_VERSION),current)
 
 .PHONY: recovery-snapshot
 recovery-snapshot: $(SOONG_RECOVERY_SNAPSHOT_ZIP)
 
 $(call dist-for-goals, recovery-snapshot, $(SOONG_RECOVERY_SNAPSHOT_ZIP))
 
-else # BOARD_VNDK_VERSION is NOT set to 'current'
+else # RECOVERY_SNAPSHOT_VERSION is NOT set to 'current'
 
 .PHONY: recovery-snapshot
 recovery-snapshot: PRIVATE_MAKEFILE := $(current_makefile)
 recovery-snapshot:
 	$(call echo-error,$(PRIVATE_MAKEFILE),\
-		"CANNOT generate Recovery snapshot. BOARD_VNDK_VERSION must be set to 'current'.")
+		"CANNOT generate Recovery snapshot. RECOVERY_SNAPSHOT_VERSION must be set to 'current'.")
 	exit 1
 
-endif # BOARD_VNDK_VERSION
+endif # RECOVERY_SNAPSHOT_VERSION