Simplify bool parsing am: 8aa7e9be3e am: 631fdff301 am: f9ec45d890

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

Change-Id: I6a058c73b399ad4636869cb2a0cac8980f2c91af
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>