Fix comment marker in METADATA file. am: d48b00960e

Original change: https://android-review.googlesource.com/c/platform/external/geonames/+/2255372

Change-Id: Ib497591e5352db5fc7139d9c578edd727962a38a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>