Move Android's build_output_dirs target to its own file.

build/all_android.gyp

Index: build/all_android.gyp
diff --git a/build/all_android.gyp b/build/all_android.gyp
index 26df56328fdcddb0c293b018daa2928a5f324bef..2a263494c42c3301b29a048e8465f4b8ff584bc5 100644
--- a/build/all_android.gyp
+++ b/build/all_android.gyp
@@ -119,35 +119,5 @@
         '../content/content.gyp:content_browsertests',
       ],
     },
-    {
-      # Target for creating common output build directories. Creating output
-      # dirs beforehand ensures that build scripts can assume these folders to
-      # exist and there are no race conditions resulting from build scripts
-      # trying to create these directories.
-      # The build/java.gypi target depends on this target.
-      'target_name': 'build_output_dirs',
-      'type': 'none',
-      'actions': [
-        {
-          'action_name': 'create_java_output_dirs',
-          'variables' : {
-          'output_dirs' : [
-            '<(PRODUCT_DIR)/apks',
-            '<(PRODUCT_DIR)/lib.java',
-            '<(PRODUCT_DIR)/test.lib.java',
-           ]
-          },
-          'inputs' : [],
-          'outputs': [
-            '<@(output_dirs)'
-          ],
-          'action': [
-            'mkdir',
-            '-p',
-            '<@(output_dirs)',
-          ],
-        },
-      ],
-    }, # build_output_dirs
   ],  # targets
 }