[incfs] Add support of special procfs link paths am: d8f2a564ac am: e275f8d7c9 am: e37ee90097 am: 2dae38acdd

Original change: https://android-review.googlesource.com/c/platform/system/incremental_delivery/+/1966132

Change-Id: I1dd652262ef4ae119a4fef3e737357efaf9cd011