Add R8 support to Soong.

Move R8_COMPAT_PROGUARD definition to Soong.
Copy the proguard_dictionary file so that the find
command that builds proguard_dict.zip can find it.

Test: m checkbuild
Change-Id: I28b2fce26ccb6225be0bd71802a43fe63df85daa
diff --git a/core/soong_app_prebuilt.mk b/core/soong_app_prebuilt.mk
index 0059e51..65aabff 100644
--- a/core/soong_app_prebuilt.mk
+++ b/core/soong_app_prebuilt.mk
@@ -27,6 +27,13 @@
     $(intermediates.COMMON)/jacoco-report-classes.jar)
 endif
 
+ifdef LOCAL_SOONG_PROGUARD_DICT
+  $(eval $(call copy-one-file,$(LOCAL_SOONG_PROGUARD_DICT),\
+    $(intermediates.COMMON)/proguard_dictionary))
+  $(call add-dependency,$(LOCAL_BUILT_MODULE),\
+    $(intermediates.COMMON)/proguard_dictionary)
+endif
+
 ifneq ($(TURBINE_DISABLED),false)
 ifdef LOCAL_SOONG_HEADER_JAR
 $(eval $(call copy-one-file,$(LOCAL_SOONG_HEADER_JAR),$(full_classes_header_jar)))