Move hiddenapi singleton rules to Soong

Hiddenapi rules are now in build/soong/java/hiddenapi_singleton.go.
This effectively requires any module in PRODUCT_BOOT_JARS to be
defined in Soong.

Bug: 123645297
Test: m checkbuild
Change-Id: If72bd1c20b2014d0a3d400624d37fdb0a3052245
diff --git a/CleanSpec.mk b/CleanSpec.mk
index f05410d..023d5e7 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -544,6 +544,8 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/product_services)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/product_services)
 
+# Clean up old location of hiddenapi files
+$(call add-clean-step, rm -f $(TARGET_OUT_COMMON_INTERMEDIATES)/PACKAGING/hiddenapi*)
 
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST