title: permission MODIFY_PHONE_STATE doesnot work
body: <p>i am working on call blocking app for android 2.2
  this permission does not work for me</p>
  
  <pre><code>android.permission.MODIFY_PHONE_STATE
  </code></pre>
  
  <p>and it gives the following error</p>
  
  <pre><code>Permission is only granted to system apps
  </code></pre>
  
  <p>will my app work without this permission ???
  or any other solution..</p>