Archive LICENSE file and copy that when updating prebuilts.

R=ricow@google.com

Change-Id: If62129d775dff13e29c48aa7d435be3b5aed0b8c
diff --git a/tools/archive.py b/tools/archive.py
index 8e7436b..2e83649 100755
--- a/tools/archive.py
+++ b/tools/archive.py
@@ -94,7 +94,8 @@
                  utils.R8_EXCLUDE_DEPS_JAR,
                  utils.COMPATDX_JAR,
                  utils.COMPATPROGUARD_JAR,
-                 utils.MAVEN_ZIP]:
+                 utils.MAVEN_ZIP,
+                 utils.GENERATED_LICENSE]:
       file_name = os.path.basename(file)
       tagged_jar = os.path.join(temp, file_name)
       shutil.copyfile(file, tagged_jar)