AsyncTask fires error message while trying to get tokens

Im trying to get the tokens in background for authenticating myself with google playservices but Im unable to do so.

My code to get token is as follows,

private class GetTokenTask extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... params) {
            try {
                return fetchToken(params[0]);
            } catch (IOException e) {
                return null;
            }
        }

        @Override
        protected void onPostExecute(String result) {
            if (result != null) {
                ProximityApi.getInstance(MainActivity.this)
                        .setAuthToken(result);
                setResult(RESULT_OK);
                finish();
            }
        }
    }

The error response that I get is as follows,

10-06 03:05:08.855    1876-1893/com.infotech.palmtree.proxybeacon W/art﹕ Suspending all threads took: 21.270ms
10-06 03:05:11.402    1876-1893/com.infotech.palmtree.proxybeacon W/art﹕ Suspending all threads took: 65.002ms
10-06 03:05:11.463    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ com.google.android.gms.auth.UserRecoverableAuthException: DeviceManagementSyncDisabled
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.google.android.gms.auth.GoogleAuthUtil.zza(Unknown Source)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.google.android.gms.auth.GoogleAuthUtil.getToken(Unknown Source)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.google.android.gms.auth.GoogleAuthUtil.getToken(Unknown Source)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.google.android.gms.auth.GoogleAuthUtil.getToken(Unknown Source)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.infotech.palmtree.proxybeacon.MainActivity.fetchToken(MainActivity.java:106)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.infotech.palmtree.proxybeacon.MainActivity.access$100(MainActivity.java:24)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.infotech.palmtree.proxybeacon.MainActivity$GetTokenTask.doInBackground(MainActivity.java:87)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at com.infotech.palmtree.proxybeacon.MainActivity$GetTokenTask.doInBackground(MainActivity.java:82)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at android.os.AsyncTask$2.call(AsyncTask.java:292)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at java.util.concurrent.FutureTask.run(FutureTask.java:237)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
10-06 03:05:11.634    1876-2140/com.infotech.palmtree.proxybeacon W/System.err﹕ at java.lang.Thread.run(Thread.java:818)
10-06 03:05:11.635    1876-2140/com.infotech.palmtree.proxybeacon I/Timeline﹕ Timeline: Activity_launch_request id:com.google.android.gms time:6855445
10-06 03:05:11.722    1876-1876/com.infotech.palmtree.proxybeacon I/Timeline﹕ Timeline: Activity_launch_request id:com.google.android.gms time:6855532

The error is self explanatory. This: UserRecoverableAuthException: DeviceManagementSyncDisabled seems to be the root cause. (Explanation of the said error)

I would assume you need to enable sync on your testing device and that should resolve the error.

PS: the following text in logs is because the Auth failed.