Strip all multidex files, not just classes.dex

Bug: 10447095
Change-Id: I6053ca97cb0e28621262a385d57c0996e7c1aaab
diff --git a/core/dex_preopt.mk b/core/dex_preopt.mk
index ab970f9..76fc130 100644
--- a/core/dex_preopt.mk
+++ b/core/dex_preopt.mk
@@ -18,7 +18,11 @@
 
 # $(1): the .jar or .apk to remove classes.dex
 define dexpreopt-remove-classes.dex
-$(hide) $(AAPT) remove $(1) classes.dex
+$(hide) zip --quiet --delete $(1) classes.dex; \
+dex_index=2; \
+while zip --quiet --delete $(1) classes$${dex_index}.dex > /dev/null; do \
+  let dex_index=dex_index+1; \
+done
 endef
 
 # Special rules for building stripped boot jars that override java_library.mk rules