Merge "Revert "Merge "Revert "towctrans() should return the input and set errno on failure."" into android15-tests-dev am: fd55858120"" into main am: 81132381ff am: f5e9831044

Original change: https://android-review.googlesource.com/c/platform/bionic/+/3272669

Change-Id: I5d10fad79d963953f6c68221f15198471033f611
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>