Remove unneeded art::Unit member functions am: 6ff274b4a0 am: f8a005ef84 am: 5e77a4ec74 am: c4b1ccf814 am: 9a05569c6c

Original change: https://android-review.googlesource.com/c/platform/art/+/2200113

Change-Id: Iadf44f7c1190d49ad32a304cde02210331c7e519
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>