Forcefully remove dirty projects if option '--force-remove-dirty' is given.
The '--force-remove-dirty' option can be used to remove previously used
projects with uncommitted changes. WARNING: This may cause data to be lost
since uncommitted changes may be removed with projects that no longer exist
in the manifest.
Change-Id: I844a6e943ded522fdc7b1b942c0a1269768054bc