Don't duplicate interfaces in iftable
Don't duplicate interfaces in iftable

Mirroring AOSP Change Idb4a13ca
https://android-review.googlesource.com//#/c/30900/

Change-Id: I5d5a7b2993f8a9b2d96cb3e80c1d47d3b994c1ae

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst