Add removed.txt for doclava api consistency check

BUG: b/11293324
Change-Id: Ie7cda9bc7d3a1e6c433eb073cc878b149cead8a0
diff --git a/core/config.mk b/core/config.mk
index 1390281..f00158e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -482,6 +482,7 @@
     $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android.jar)))
 
 INTERNAL_PLATFORM_API_FILE := $(TARGET_OUT_COMMON_INTERMEDIATES)/PACKAGING/public_api.txt
+INTERNAL_PLATFORM_REMOVED_API_FILE := $(TARGET_OUT_COMMON_INTERMEDIATES)/PACKAGING/removed.txt
 
 # This is the standard way to name a directory containing prebuilt target
 # objects. E.g., prebuilt/$(TARGET_PREBUILT_TAG)/libc.so