build: Add installer persistence support [1/3]

Was commented out in the 4.4.x merge of build/

This reverts commit decc8f09860ecbda70fb0a3100b24cf24aa0ba1b.

Change-Id: I64984097ac43d58ea02bb45775341669d595c6fb
Merge branch 'kitkat' of https://github.com/AOKP/build into kitkat