Remove Core Library JARs from `/system/framework`.

These JARs are part of the ART APEX, and are now located in
`/apex/com.android.art/javalib`. Remove the supernumerary copies in
`/system/framework` and save ~11 MiB on the system partition.

(cherry picked from commit d4f09f77520f914bbd5d53ded9ac6188b2cd31b5)

Test: Device boot test
Bug: 142944799
Change-Id: Ia6f58d858ecdb80c9701696b8f20d5fa2de0c2c7
Merged-In: Ia6f58d858ecdb80c9701696b8f20d5fa2de0c2c7
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 8219afc..97fea05 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -681,6 +681,10 @@
 # Migrate preopt files to system_other for some devices
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/*/*app/*/oat)
 
+# Remove Android Core Library artifacts from the system partition, now
+# that they live in the ART APEX (b/142944799).
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/framework/*.jar)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************