[windows] Fix std::stringstream error after upgrading libc++ am: 81243c9d8f am: 841ef90e4a am: 4a4ffce8be

Original change: https://android-review.googlesource.com/c/platform/external/openscreen/+/2898092

Change-Id: I6164bf34211e7bb16e1614a673f33b93bb01cb11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>