title: API Change error when building AOSP 5.1
body: <p>Currently trying to build android-5.1.0_r5. I've checked out the sources and made no modifications. However, when compiling I get the following error.</p>
  
  <pre><code>Checking API: checkpublicapi-current
  out/target/common/obj/PACKAGING/public_api.txt:20: error 5: Added public field android.Manifest.permission.BACKUP
  out/target/common/obj/PACKAGING/public_api.txt:82: error 5: Added public field android.Manifest.permission.INVOKE_CARRIER_SETUP
  out/target/common/obj/PACKAGING/public_api.txt:106: error 5: Added public field android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE
  out/target/common/obj/PACKAGING/public_api.txt:116: error 5: Added public field android.Manifest.permission.RECEIVE_EMERGENCY_BROADCAST
  
  ******************************
  You have tried to change the API from what has been previously approved.
  
  To make these errors go away, you have two choices:
     1) You can add "@hide" javadoc comments to the methods, etc. listed in the
        errors above.
  
     2) You can update current.txt by executing the following command:
           make update-api
  
        To submit the revised current.txt to the main Android repository,
        you will need approval.
  ******************************
  </code></pre>
  
  <p>And diffing the public api txt files does indeed show a difference. </p>
  
  <pre><code>diff frameworks/base/api/current.txt out/target/common/obj/PACKAGING/public_api.txt 
  19a20
  &gt;     field public static final java.lang.String BACKUP = "android.permission.BACKUP";
  80a82
  &gt;     field public static final java.lang.String INVOKE_CARRIER_SETUP = "android.permission.INVOKE_CARRIER_SETUP";
  103a106
  &gt;     field public static final java.lang.String READ_PRIVILEGED_PHONE_STATE = "android.permission.READ_PRIVILEGED_PHONE_STATE";
  112a116
  &gt;     field public static final java.lang.String RECEIVE_EMERGENCY_BROADCAST = "android.permission.RECEIVE_EMERGENCY_BROADCAST";
  </code></pre>
  
  <p>However, I cant figure out where those additional Public Fields are coming from. Any ideas?</p>