Reduce the propagation of LOCAL_DEX_PREOPT := nostripping

nostripping causes confusing double negatives, allow nostripping
in LOCAL_DEX_PREOPT and DEFAULT_DEX_PREOPT, but convert to
LOCAL_STRIP_DEX outside of dex_preopt_odex_install.mk.

Test: m checkbuild
Change-Id: I996e9258ce20c394900d9fe937d638bc2ab8589d
diff --git a/core/soong_app_prebuilt.mk b/core/soong_app_prebuilt.mk
index d34f367..31cb28e 100644
--- a/core/soong_app_prebuilt.mk
+++ b/core/soong_app_prebuilt.mk
@@ -69,7 +69,7 @@
 ifdef LOCAL_DEX_PREOPT
   $(built_odex): $(LOCAL_SOONG_DEX_JAR)
 	$(call dexpreopt-one-file,$<,$@)
-  $(eval $(call dexpreopt-copy-jar,$(LOCAL_PREBUILT_MODULE_FILE),$(LOCAL_BUILT_MODULE),$(LOCAL_DEX_PREOPT)))
+  $(eval $(call dexpreopt-copy-jar,$(LOCAL_PREBUILT_MODULE_FILE),$(LOCAL_BUILT_MODULE),$(LOCAL_STRIP_DEX)))
 else
   $(eval $(call copy-one-file,$(LOCAL_PREBUILT_MODULE_FILE),$(LOCAL_BUILT_MODULE)))
 endif