title: Android wear sample code exception
body: <p>Afrer I build the sample code and install it on my Nexus 4.
  I use Eclipse and import WearableNotificationsSample, ElizaChat sample code of AndroidWearPreview.
  It failed. why?</p>
  
  <pre><code>03-20 14:34:34.418: E/AndroidRuntime(9989): Process: com.example.android.preview.support.wearable.notifications, PID: 9989
  03-20 14:34:34.418: E/AndroidRuntime(9989): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.android.preview.support.wearable.notifications/com.example.android.preview.support.wearable.notifications.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.android.preview.support.wearable.notifications.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.android.preview.support.wearable.notifications-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.android.preview.support.wearable.notifications-2, /vendor/lib, /system/lib]]
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.os.Handler.dispatchMessage(Handler.java:102)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.os.Looper.loop(Looper.java:136)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread.main(ActivityThread.java:5017)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at java.lang.reflect.Method.invokeNative(Native Method)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at java.lang.reflect.Method.invoke(Method.java:515)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at dalvik.system.NativeStart.main(Native Method)
  03-20 14:34:34.418: E/AndroidRuntime(9989): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.android.preview.support.wearable.notifications.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.android.preview.support.wearable.notifications-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.android.preview.support.wearable.notifications-2, /vendor/lib, /system/lib]]
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
  03-20 14:34:34.418: E/AndroidRuntime(9989):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2112)
  </code></pre>