acloud: auto unlock screen after invoke the vnc client

Bug: 137249719
Test: atest acloud_test --host &&
acloud-dev create --unlock
acloud-dev create --local-instance --local-image --unlock
acloud-dev create --avd-type gce --build-id 5108589 --branch git_master --unlock

Change-Id: I66a9af1d87ebb8bc1f46274aa57b1e7aba979f98
11 files changed