Replace hiddenapi-{public,private}-list.txt with a CSV file

`hiddenapi` is being refactored to work with a single CSV file as
opposued to a multitude of text files (one per flag). This patch
changes the singleton rule for listing public/private APIs from
stubs to expect a CSV as an output.

Bug: 119068555
Test: compiles, hiddenapi-flags.csv unchanged
Change-Id: If56c7ab8a4c3bbd33e447ef0dfd33f2c303a937c
diff --git a/core/soong_config.mk b/core/soong_config.mk
index 1b6b9d3..5201a62 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -152,7 +152,7 @@
 $(call add_json_bool, EnforceSystemCertificate,          $(ENFORCE_SYSTEM_CERTIFICATE))
 $(call add_json_list, EnforceSystemCertificateWhitelist, $(ENFORCE_SYSTEM_CERTIFICATE_WHITELIST))
 
-$(call add_json_str,  HiddenAPIPublicList,               $(INTERNAL_PLATFORM_HIDDENAPI_PUBLIC_LIST))
+$(call add_json_str,  HiddenAPIStubFlags,                $(INTERNAL_PLATFORM_HIDDENAPI_STUB_FLAGS))
 $(call add_json_str,  HiddenAPIFlags,                    $(INTERNAL_PLATFORM_HIDDENAPI_FLAGS))
 $(call add_json_list, HiddenAPIExtraAppUsageJars,        $(HIDDENAPI_EXTRA_APP_USAGE_JARS))