Fix naming according to the Rust styleguide. am: 192e0bbc0f

Original change: https://android-review.googlesource.com/c/platform/system/tools/sysprop/+/2743333

Change-Id: Iefb05e2492eafe781684d18306896fd789c48296
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>