Delete apidiff.mk

Also remove the msg.mk files used for old apicheck.

And export jdiff-doc.zip generated by Soong.

Test: api-stubs-docs-diff
Bug: b/78245848
Change-Id: I329aa375623a7b7a121d58314dab694a326c9f0f
diff --git a/core/config.mk b/core/config.mk
index 676f325..676bd64 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -85,6 +85,7 @@
 $(KATI_obsolete_var PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE,Set FCM Version in device manifest instead. See $(CHANGES_URL)#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE)
 $(KATI_obsolete_var USE_CLANG_PLATFORM_BUILD,Clang is the only supported Android compiler. See $(CHANGES_URL)#USE_CLANG_PLATFORM_BUILD)
 $(KATI_obsolete_var BUILD_DROIDDOC,Droiddoc is only supported in Soong. See details on build/soong/java/droiddoc.go)
+$(KATI_obsolete_var BUILD_APIDIFF,Apidiff is only supported in Soong. See details on build/soong/java/droiddoc.go)
 $(KATI_obsolete_var \
   DEFAULT_GCC_CPP_STD_VERSION \
   HOST_GLOBAL_CFLAGS 2ND_HOST_GLOBAL_CFLAGS \
@@ -174,7 +175,6 @@
 BUILD_JAVA_LIBRARY:= $(BUILD_SYSTEM)/java_library.mk
 BUILD_STATIC_JAVA_LIBRARY:= $(BUILD_SYSTEM)/static_java_library.mk
 BUILD_HOST_JAVA_LIBRARY:= $(BUILD_SYSTEM)/host_java_library.mk
-BUILD_APIDIFF:= $(BUILD_SYSTEM)/apidiff.mk
 BUILD_COPY_HEADERS := $(BUILD_SYSTEM)/copy_headers.mk
 BUILD_NATIVE_TEST := $(BUILD_SYSTEM)/native_test.mk
 BUILD_NATIVE_BENCHMARK := $(BUILD_SYSTEM)/native_benchmark.mk