Using LOCAL_DROIDDOC_STUB_OUT_DIR to specify "-stubs" option.

So that the build system can clean up the stub out dir before
calling doclava.

Bug: 22534021
Change-Id: Iba33cf0a295e4ae32fdcad8bd326c2f52de5f875
diff --git a/Android.mk b/Android.mk
index ccbd9c9..19fe2f7 100644
--- a/Android.mk
+++ b/Android.mk
@@ -809,9 +809,10 @@
 
 LOCAL_MODULE := api-stubs
 
+LOCAL_DROIDDOC_STUB_OUT_DIR := $(TARGET_OUT_COMMON_INTERMEDIATES)/JAVA_LIBRARIES/android_stubs_current_intermediates/src
+
 LOCAL_DROIDDOC_OPTIONS:=\
 		$(framework_docs_LOCAL_DROIDDOC_OPTIONS) \
-		-stubs $(TARGET_OUT_COMMON_INTERMEDIATES)/JAVA_LIBRARIES/android_stubs_current_intermediates/src \
 		-api $(INTERNAL_PLATFORM_API_FILE) \
 		-removedApi $(INTERNAL_PLATFORM_REMOVED_API_FILE) \
 		-nodocs
@@ -841,9 +842,10 @@
 
 LOCAL_MODULE := system-api-stubs
 
+LOCAL_DROIDDOC_STUB_OUT_DIR := $(TARGET_OUT_COMMON_INTERMEDIATES)/JAVA_LIBRARIES/android_system_stubs_current_intermediates/src
+
 LOCAL_DROIDDOC_OPTIONS:=\
 		$(framework_docs_LOCAL_DROIDDOC_OPTIONS) \
-		-stubs $(TARGET_OUT_COMMON_INTERMEDIATES)/JAVA_LIBRARIES/android_system_stubs_current_intermediates/src \
 		-showAnnotation android.annotation.SystemApi \
 		-api $(INTERNAL_PLATFORM_SYSTEM_API_FILE) \
 		-removedApi $(INTERNAL_PLATFORM_SYSTEM_REMOVED_API_FILE) \