Update multidex tools.

Update up to dalvik master commit: 7fd86ebf6ea41f8e367866f127a593bad849a8cb
Includes:
- Force dx compilation target to java 6.
- Make a better detection of index limit in multidex.
- Split multicatch so they have different handlers.
- Return the correct error code in multi-thread mode
- Keep all annotation in main dex.
- Transform incorrect invokevirtual ops to invokedirect.

Change-Id: I0f6033475e76abee918918e5b47972abbb701d16
diff --git a/tools/mainDexClasses.rules b/tools/mainDexClasses.rules
index f57cbdd..af4085a 100644
--- a/tools/mainDexClasses.rules
+++ b/tools/mainDexClasses.rules
@@ -20,3 +20,8 @@
   -keep public class * extends android.app.backup.BackupAgent {

    <init>();

   }

+# We need to keep all annotation classes because proguard does not trace annotation attribute

+# it just filter the annotation attributes according to annotation classes it already kept.

+  -keep public class * extends java.lang.annotation.Annotation {

+   *;

+  }