Add lock_path as param to remove_external function

commit b0d0c335 added remove external lock file function, but
the lock_path as lock file location folder is missing and
it make it's impossible to specify where to find the lock file.
This patch added the params.

Change-Id: I9be2fb68fab4690993395d01ef5ad13c0c92f3a3
Related-Bug: #1256306
Merge "Add lock_path as param to remove_external function"