Include root in mainline_system artifact claim.

With PRODUCT_SHIPPING_API_LEVEL >= 28, system-as-root is implied.
Remove redundant whitelist entries.

Bug: 80410283
Test: lunch mainline_arm64; m nothing
Change-Id: Ia18ef42525a3abb33842e939c389530ed299aafe
diff --git a/target/product/mainline_system.mk b/target/product/mainline_system.mk
index 96365b5..651ece6 100644
--- a/target/product/mainline_system.mk
+++ b/target/product/mainline_system.mk
@@ -37,17 +37,14 @@
 _base_mk_whitelist := \
   $(_selinux_policy_whitelist) \
   recovery/root/etc/mke2fs.conf \
-  root/init \
-  root/init.environ.rc \
-  root/init.rc \
-  root/init.usb.configfs.rc \
-  root/init.usb.rc \
-  root/init.zygote32.rc \
-  root/sbin/charger \
-  root/ueventd.rc \
   vendor/lib/mediadrm/libdrmclearkeyplugin.so \
   vendor/lib64/mediadrm/libdrmclearkeyplugin.so \
 
 _my_whitelist := $(_base_mk_whitelist)
 
-$(call require-artifacts-in-path, $(TARGET_COPY_OUT_SYSTEM), $(_my_whitelist))
+# Both /system and / are in system.img when PRODUCT_SHIPPING_API_LEVEL>=28.
+_my_paths := \
+  $(TARGET_COPY_OUT_ROOT) \
+  $(TARGET_COPY_OUT_SYSTEM) \
+
+$(call require-artifacts-in-path, $(_my_paths), $(_my_whitelist))