Here are the permission commands:
adb shell pm uninstall -k --user 0 com.lge.voicecommand
adb shell appops set com.android.cts.virresh.kcomouse SYSTEM_ALERT_WINDOW allow
adb shell settings put secure accessibility_enabled 1
adb shell settings put secure enabled_accessibility_services com.android.cts.virresh.kcomouse/com.android.cts.virresh.kcomouse.services.MouseEventService
adb shell am startservice com.android.cts.virresh.kcomouse/com.android.cts.virresh.kcomouse.services.MouseEventService
and here is the commands to enable the mouse/voice access/ button mapper to work together:
adb shell settings put secure enabled_accessibility_services com.android.cts.flar2.homebutton/a.i:com.android.cts.apps.accessibility.voiceaccess/com.google.android.apps.accessibility.voiceaccess.JustSpeakService:com.android.cts.virresh.kcomouse/com.android.cts.virresh.kcomouse.services.MouseEventService
adb shell settings put secure accessibility_enabled 1