title: base64 decoder in android in API level 7
body: <p>How to decode a base64 encoded string to byte array on Android API level 7? </p>
  
  <p>Can it be done using any standard packages of Java?  </p>
  
  <p>Should i copy the source code from google search results?  </p>
  
  <p>Should i re-implement encoder and decoder according to RFC?  </p>
  
  <p>PS: API level 8 has util package android.util.Base64 that does this, but i have to do development based on API level 7.</p>