Add SOONG_HIDDENAPI_FLAGS as hiddenapi_flags.csv dependencies

Hiddenapi build logic has moved to soong and list of flags.csv files
is now being passed to make files through SOONG_HIDDENAPI_FLAGS
variable. Adjust the build rule for hiddenapi_flags.csv accordingly.

Test: aosp compiles
Change-Id: I930f918fb36ce3532478035e83c2632559fd07b6

Android.mk

@@ -79,6 +79,8 @@ update-api: doc-comment-check-docs
 
 # ==== hiddenapi lists =======================================
 .KATI_RESTAT: $(INTERNAL_PLATFORM_HIDDENAPI_FLAGS)
+$(INTERNAL_PLATFORM_HIDDENAPI_FLAGS): \
+    PRIVATE_FLAGS_INPUTS := $(PRIVATE_FLAGS_INPUTS) $(SOONG_HIDDENAPI_FLAGS)
 $(INTERNAL_PLATFORM_HIDDENAPI_FLAGS): \
     frameworks/base/tools/hiddenapi/generate_hiddenapi_lists.py \
     frameworks/base/config/hiddenapi-greylist.txt \
@@ -87,7 +89,8 @@ $(INTERNAL_PLATFORM_HIDDENAPI_FLAGS): \
     frameworks/base/config/hiddenapi-force-blacklist.txt \
     $(INTERNAL_PLATFORM_HIDDENAPI_PUBLIC_LIST) \
     $(INTERNAL_PLATFORM_HIDDENAPI_PRIVATE_LIST) \
-    $(INTERNAL_PLATFORM_REMOVED_DEX_API_FILE)
+    $(INTERNAL_PLATFORM_REMOVED_DEX_API_FILE) \
+    $(SOONG_HIDDENAPI_FLAGS)
 	frameworks/base/tools/hiddenapi/generate_hiddenapi_lists.py \
 	    --public $(INTERNAL_PLATFORM_HIDDENAPI_PUBLIC_LIST) \
 	    --private $(INTERNAL_PLATFORM_HIDDENAPI_PRIVATE_LIST) \