Use flags from Soong for d8 and r8

Use the flags provided by Soong when running d8 and r8.

Bug: 119270658
Test: m checkbuild
Change-Id: I9459ded386effc27c4c96f1e94f9ea2f8ed19319
diff --git a/core/definitions.mk b/core/definitions.mk
index c97f647..ca978da 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -2225,7 +2225,7 @@
 @mkdir -p $(dir $@)
 $(hide) rm -f $(dir $@)classes*.dex $(dir $@)d8_input.jar
 $(hide) $(ZIP2ZIP) -j -i $< -o $(dir $@)d8_input.jar "**/*.class"
-$(hide) $(DX_COMMAND) \
+$(hide) $(DX_COMMAND) $(DEX_FLAGS) \
     --output $(dir $@) \
     $(addprefix --lib ,$(PRIVATE_D8_LIBS)) \
     --min-api $(PRIVATE_MIN_SDK_VERSION) \
@@ -2697,7 +2697,8 @@
 define transform-jar-to-dex-r8
 @echo R8: $@
 $(hide) rm -f $(PRIVATE_PROGUARD_DICTIONARY)
-$(hide) $(R8_COMPAT_PROGUARD) -injars '$<' \
+$(hide) $(R8_COMPAT_PROGUARD) $(DEX_FLAGS) \
+    -injars '$<' \
     --min-api $(PRIVATE_MIN_SDK_VERSION) \
     --no-data-resources \
     --force-proguard-compatibility --output $(subst classes.dex,,$@) \