Qemu: Keep ssh connection to VM open. am: 902ee14fd6 am: 4a4164bb85

Original change: https://android-review.googlesource.com/c/platform/art/+/2984873

Change-Id: I9a24e06ff984d4935011e338b6f11784a0f238de
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>