title: ClassNotFoundException: Didn't find class "android.os.PersistableBundle" Otto Android 5.0
body: <p>I have a strange issue.
  I have an app which I deployed on an Android 4.4 device and use Otto library.
  I deployed the app on an Android 5.0 device. It still works.
  I retried on the 4.4 and the app won't launched.</p>
  
  <p>Apparently, it tries to use PersistableBundle.class which a API 21 class.
  Here my log :</p>
  
  <pre><code>    Caused by: java.lang.ClassNotFoundException: Didn't find class "android.os.PersistableBundle" on path: DexPathList[[zip file "/data/app/fr.myapp.apk"],nativeLibraryDirectories=[/data/app-lib/fr.myapp, /vendor/lib, /system/lib]]
              at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
              at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
              at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
              at java.lang.Class.getDeclaredMethods(Native Method)
              at java.lang.Class.getDeclaredMethods(Class.java:656)
              at com.squareup.otto.AnnotatedHandlerFinder.loadAnnotatedMethods(AnnotatedHandlerFinder.java:52)
              at com.squareup.otto.AnnotatedHandlerFinder.findAllProducers(AnnotatedHandlerFinder.java:126)
              at com.squareup.otto.HandlerFinder$1.findAllProducers(HandlerFinder.java:33)
              at com.squareup.otto.Bus.register(Bus.java:191)
  </code></pre>