Simplify bool parsing am: 8aa7e9be3e

Original change: https://android-review.googlesource.com/c/platform/system/librustutils/+/2571571

Change-Id: I40848892c0181283e9cc6932bb0f99bec50142a9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>