Fix compilation error when building with C++17 am: 3d3364efdc am: 9856c63ca7 am: a3580f608e am: 70523375c8

Original change: https://android-review.googlesource.com/c/platform/system/keymaster/+/1393269

Change-Id: I7e77a829a7f38597dcefa34fe97abf2723349255