Trim '/' When Composing Git Ref From Package Dir (#2913)
Trim '/' When Composing Git Ref From Package Dir (#2913)

Client may provide package directory with leading slash.
For defense-in-depth, trim the leading and trailing slash
when constructing the git ref to look for the package.
GoogleContainerTools/kpt,GoogleContainerTools/kpt,GoogleContainerTools/kpt,GoogleContainerTools/kpt,GoogleContainerTools/kpt