On devices running android 9 with google play services, PlayProtect
blocks the installation of our automation apks due to targeting a lower
SDK version. Update all apk builds to target SDK version 28 (Android 9)
however do not change the minimum version to maintain backwards
compatibility.
Do not concatenate start/stop markers to the action string with a '_',
delimit them with a space instead. This will make easier to parse the
message afterwards.
