vndk: workaround for building ld.config.<ver>.txt

ld.config.27.txt requires additional search paths for vendor
processes. Substitute '#VNDK27#' when building ld.config.<ver>.txt.
If <ver> equals 27, remove '#VNDK27#'. Otherwise, remove whole line
that starts with '#VNDK27#'.

Bug: 123209911
Bug: 123390078
Test: build ld.config.27.txt
Change-Id: Ie3a284ab39f17fa2f9a3285e080b2ba0da3663dc