Make com.android.sepolicy mandatory

The apex_sepolicy files were removed from the system partition in
ag/17753690 because they were not necessary in T builds.

For updatable sepolicy in Android U+ we are planning to move parts of
the existing platform policy into the apex sepolicy, so we will need to
make the apex_sepolicy files available to all builds.

Bug: 243923977
Test: adb shell ls /dev/selinux /system/etc/selinux
Change-Id: I24b8b8880149885d98caf992afdae908ead11fcf

target/product/base_system.mk

@@ -69,6 +69,7 @@ PRODUCT_PACKAGES += \
     com.android.neuralnetworks \
     com.android.scheduling \
     com.android.sdkext \
+    com.android.sepolicy \
     com.android.tethering \
     com.android.tzdata \
     com.android.uwb \
@@ -375,6 +376,7 @@ PRODUCT_SYSTEM_PROPERTIES += persist.traced.enable=1
 PRODUCT_PACKAGES_DEBUG := \
     adb_keys \
     arping \
+    com.android.sepolicy.cert-debug.der \
     dmuserd \
     idlcli \
     init-debug.rc \