Fix naming according to the Rust styleguide. am: 192e0bbc0f am: 8ffaf612d8

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

Change-Id: I981d750889ca2395efaeac645cab61c0f8add6bb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>