Now current is also a valid prebuilt SDK.

Change-Id: Id05d20f17a4b46e19df88516f50e58f6cdb62c1c
diff --git a/core/config.mk b/core/config.mk
index 3c267d9..f02fbef 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -432,7 +432,7 @@
     ( sgrax $(1) | sort -g ) )
 endef
 
-TARGET_AVAILABLE_SDK_VERSIONS := current $(call numerically_sort,\
+TARGET_AVAILABLE_SDK_VERSIONS := $(call numerically_sort,\
     $(patsubst $(HISTORICAL_SDK_VERSIONS_ROOT)/%/android.jar,%, \
     $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android.jar)))