aconfig_storage: move storage files to <partition>/etc/aconfig dir

Move them to under aconfig dir so it is easier to define SELinux policy.

Bug: b/312459182
Test: m
Change-Id: I2af7167a21e004729a9ac8628243080c893fb33a
diff --git a/core/packaging/flags.mk b/core/packaging/flags.mk
index 62ef3df..500efdd 100644
--- a/core/packaging/flags.mk
+++ b/core/packaging/flags.mk
@@ -154,9 +154,9 @@
 
 ifeq ($(RELEASE_CREATE_ACONFIG_STORAGE_FILE),true)
 $(foreach partition, $(_FLAG_PARTITIONS), \
-	$(eval aconfig_storage_package_map.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/package.map) \
-	$(eval aconfig_storage_flag_map.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/flag.map) \
-	$(eval aconfig_storage_flag_val.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/flag.val) \
+	$(eval aconfig_storage_package_map.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/aconfig/package.map) \
+	$(eval aconfig_storage_flag_map.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/aconfig/flag.map) \
+	$(eval aconfig_storage_flag_val.$(partition) := $(PRODUCT_OUT)/$(partition)/etc/aconfig/flag.val) \
 	$(eval $(call generate-partition-aconfig-storage-file, \
 				$(TARGET_OUT_FLAGS)/$(partition)/package.map, \
 				$(TARGET_OUT_FLAGS)/$(partition)/flag.map, \