Add Looper.prepare() to doInBackground()

Fix runtime error that was being thrown as Looper.prepare() was not called
in the async function doInBackground.

Bug: 124612105

Test: Was not able to reproduce the bug (that is make code execution flow
through the catch block).
* Reproduced by throwing IOException in the try block so that code flows
  to the catch block.
* Build and flash.
* Take interactive bugreport and change title and name of the bugreport from
  the progress bar.

Change-Id: I6a5ea594d95462e1c66bd28eb81dd5f4daa6f35e