Adapt to changes in Gerrit plugin API With [1] the package for NativeString and Natives was changed so that the imports needed to be adapted. NativeMap and TransformCallback are now available in the plugin API. [1] https://gerrit-review.googlesource.com/54375 Change-Id: I6116f21fe2f1778c608ee100fd94c1f479f94976 Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>