pywalt: fix stuck communication am: de48cf557f am: 842e8b8860 am: 26b4ade211 am: d215878a4c

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/walt/+/12239743

Change-Id: I37f1b5df6ca330bc202037176a10bbdbb5656897