[automerger skipped] Add debug log for tracking NPE of mMobileIfaces am: b8364adc23 -s ours am: 59866338f2 -s ours

am skip reason: Merged-In Ib048c18b1c64627de5a9d2b04d10e084a014ff64 with SHA-1 d01d83654b is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15406353

Change-Id: I1dd2a3d06505ee145fc9f000a6bc32f90def807d