jflte: clean up prop extraction process

* don't kill the blobs/ dir on /system so that it may be pulled
  from via extract_files
* this allows us to clean up the amazing mess i've created for
  the entire extract_files process

Change-Id: Ib93061faa693abf9762e56016c0b825a2494a3d4
jflteatt: Update init to I337UCUFNB1 (4.4.2)

This also aligns the ro.product.model with stock.

Change-Id: Ib783eaa3a4bc052704efeae99e0bc45fbc2aa1ab