Marks itoa available in OEM apexes. am: b7faf345e7

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/itoa/+/3247111

Change-Id: I18618560ea7f5f001f2bf28d1c7a6fd353a7b029
Signed-off-by: Automerger Merge Worker <[email protected]>