Add optional timeout to PropertyWatcher::wait. am: 9349cf0598 am: 6bf2d6abc3 am: 7168a32209 am: 091f367b37 am: c4daacacc3 am: 2ba2eb9c29

Original change: https://android-review.googlesource.com/c/platform/system/librustutils/+/2584503

Change-Id: I56bdc442c16d6bb3bdfa9b6d16342c067e3710e6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>