MAP: Handle following cleanup for MAPS:

- Remove MNS notificationReg pending messages  before
  requesting MNS connect for saved request.

- Handle dynamic email account SDP even when MAS connected.

- Move AppObserver Account and emailContentObserver onChange()
  handling to worker threads instead of main thread.

Change-Id: I557213da4f1080b44809a5f78d51d58c385cb8f0
CRs-Fixed: 921943