Make aar_embedded_jar_extractor.py not try to recreate the output directory.

--
MOS_MIGRATED_REVID=138516288
diff --git a/tools/android/aar_embedded_jars_extractor.py b/tools/android/aar_embedded_jars_extractor.py
index 22326ef..e631c48 100644
--- a/tools/android/aar_embedded_jars_extractor.py
+++ b/tools/android/aar_embedded_jars_extractor.py
@@ -18,7 +18,6 @@
 of the jars and creates a param file for singlejar to merge them into one jar.
 """
 
-import os
 import re
 import sys
 import zipfile
@@ -37,7 +36,6 @@
 
 
 def ExtractEmbeddedJars(aar, singlejar_param_file, output_dir):
-  os.makedirs(output_dir)
   jar_pattern = re.compile("^(classes|libs/.+)\\.jar$")
   singlejar_param_file.write("--exclude_build_data\n")
   for name in aar.namelist():
diff --git a/tools/android/aar_embedded_jars_extractor_test.py b/tools/android/aar_embedded_jars_extractor_test.py
index 9f4dca3..30f150e 100644
--- a/tools/android/aar_embedded_jars_extractor_test.py
+++ b/tools/android/aar_embedded_jars_extractor_test.py
@@ -35,6 +35,7 @@
   def testNoJars(self):
     aar = zipfile.ZipFile(StringIO.StringIO(), "w")
     param_file = StringIO.StringIO()
+    os.makedirs("out_dir")
     aar_embedded_jars_extractor.ExtractEmbeddedJars(aar, param_file, "out_dir")
     self.assertEqual([], os.listdir("out_dir"))
     param_file.seek(0)
@@ -46,6 +47,7 @@
     aar.writestr("libs/a.jar", "")
     aar.writestr("libs/b.jar", "")
     param_file = StringIO.StringIO()
+    os.makedirs("out_dir")
     aar_embedded_jars_extractor.ExtractEmbeddedJars(aar, param_file, "out_dir")
     self.assertItemsEqual(["classes.jar", "libs"], os.listdir("out_dir"))
     self.assertItemsEqual(["a.jar", "b.jar"], os.listdir("out_dir/libs"))
@@ -64,6 +66,7 @@
     aar = zipfile.ZipFile(StringIO.StringIO(), "w")
     aar.writestr("classes.jar", "")
     param_file = StringIO.StringIO()
+    os.makedirs("out_dir")
     aar_embedded_jars_extractor.ExtractEmbeddedJars(aar, param_file, "out_dir")
     self.assertEqual(["classes.jar"], os.listdir("out_dir"))
     param_file.seek(0)