abitidy: include iomanip header am: ea94d3dbe7

Original change: https://android-review.googlesource.com/c/platform/external/libabigail/+/2379788

Change-Id: I97c7604e9bc9e017c7ae574555e336da39864ee3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>