am b9a17931: Merge "SipSession: make potential time-consuming ops run on background thread" into gingerbread

Merge commit 'b9a1793195853d6f4a8656d029f0ab47a544d31d' into gingerbread-plus-aosp

* commit 'b9a1793195853d6f4a8656d029f0ab47a544d31d':
  SipSession: make potential time-consuming ops run on background thread