Add missing comma. am: 8ac651fcf5 am: a7e6e25174 am: 353f0baaeb

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/shared_child/+/1905771

Change-Id: I7a1171ffa6973b1bbea87477ba16d245a85d6eea