Add back removed 'rm -rf' command in vulcanize rule
Add back removed 'rm -rf' command in vulcanize rule

The command was inadvertently removed in Change Ib2ef8dff94.

Bug: Issue 4074
Change-Id: Ifc73353a6cbe223bea7c570d50b6e77445a2fc6b

joshuawilson/merrit,gerrit-review/gerrit,gerrit-review/gerrit,WANdisco/gerrit,WANdisco/gerrit,joshuawilson/merrit,joshuawilson/merrit,WANdisco/gerrit,GerritCodeReview/gerrit,MerritCR/merrit,GerritCodeReview/gerrit,gerrit-review/gerrit,MerritCR/merrit,joshuawilson/merrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,MerritCR/merrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,gerrit-review/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,MerritCR/merrit,gerrit-review/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,gerrit-review/gerrit,GerritCodeReview/gerrit,joshuawilson/merrit,MerritCR/merrit,joshuawilson/merrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,WANdisco/gerrit,joshuawilson/merrit,MerritCR/merrit,MerritCR/merrit,gerrit-review/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,MerritCR/merrit,joshuawilson/merrit,WANdisco/gerrit