Merged and dist lists of unused methods from R8

Merge all the proguard_usage.zip files produced by the R8 rules and
dist the result.

Bug: 151857441
Test: m TARGET_BUILD_APPS=DocumentsUI dist
Change-Id: I7e6d73241478016093a203dc7bd86407ab86a4ac
diff --git a/core/soong_app_prebuilt.mk b/core/soong_app_prebuilt.mk
index b994b17..50ac93a 100644
--- a/core/soong_app_prebuilt.mk
+++ b/core/soong_app_prebuilt.mk
@@ -7,6 +7,7 @@
 # LOCAL_SOONG_HEADER_JAR
 # LOCAL_SOONG_JACOCO_REPORT_CLASSES_JAR
 # LOCAL_SOONG_PROGUARD_DICT
+# LOCAL_SOONG_PROGUARD_USAGE
 # LOCAL_SOONG_RESOURCE_EXPORT_PACKAGE
 # LOCAL_SOONG_RRO_DIRS
 # LOCAL_SOONG_JNI_LIBS_$(TARGET_ARCH)
@@ -85,6 +86,13 @@
     $(intermediates.COMMON)/proguard_dictionary)
 endif
 
+ifdef LOCAL_SOONG_PROGUARD_USAGE_ZIP
+  $(eval $(call copy-one-file,$(LOCAL_SOONG_PROGUARD_USAGE_ZIP),\
+    $(intermediates.COMMON)/proguard_usage.zip))
+  $(call add-dependency,$(LOCAL_BUILT_MODULE),\
+    $(intermediates.COMMON)/proguard_usage.zip)
+endif
+
 ifdef LOCAL_SOONG_RESOURCE_EXPORT_PACKAGE
 resource_export_package := $(intermediates.COMMON)/package-export.apk
 resource_export_stamp := $(intermediates.COMMON)/src/R.stamp