Qemu: Also use ssh_config during setup&sync

Speed up ssh connections and avoid messages about changed VM keys.

Test: art/tools/buildbot-sync.sh
Change-Id: Ida942ee65e48da514797281f095f24294e437593
diff --git a/tools/buildbot-utils.sh b/tools/buildbot-utils.sh
index 1cdd275..78d2243 100755
--- a/tools/buildbot-utils.sh
+++ b/tools/buildbot-utils.sh
@@ -78,13 +78,14 @@
     msgfatal "ART_TEST_SSH_PORT not set"
   fi
 
+  SSH_CONFIG=$ANDROID_BUILD_TOP/art/test/testrunner/ssh_config
   export ART_TEST_CHROOT_BASENAME="art-test-chroot"
   export ART_TEST_CHROOT="/home/$ART_TEST_SSH_USER/$ART_TEST_CHROOT_BASENAME"
   export ART_CHROOT_CMD="unshare --user --map-root-user chroot $ART_TEST_CHROOT_BASENAME"
-  export ART_SSH_CMD="ssh -q -i ~/.ssh/ubuntu -p $ART_TEST_SSH_PORT -o StrictHostKeyChecking=no $ART_TEST_SSH_USER@$ART_TEST_SSH_HOST"
-  export ART_SCP_CMD="scp -i ~/.ssh/ubuntu -o StrictHostKeyChecking=no -P $ART_TEST_SSH_PORT -p -r"
+  export ART_SSH_CMD="ssh -q -F $SSH_CONFIG -p $ART_TEST_SSH_PORT $ART_TEST_SSH_USER@$ART_TEST_SSH_HOST"
+  export ART_SCP_CMD="scp -q -F $SSH_CONFIG -P $ART_TEST_SSH_PORT -p -r"
   export ART_RSYNC_CMD="rsync -az"
-  export RSYNC_RSH="ssh -i ~/.ssh/ubuntu -p $ART_TEST_SSH_PORT -o StrictHostKeyChecking=no" # don't prefix with "ART_", rsync expects this name
+  export RSYNC_RSH="ssh -q -F $SSH_CONFIG -p $ART_TEST_SSH_PORT" # don't prefix with "ART_", rsync expects this name
 
   if [[ "$TARGET_ARCH" =~ ^(arm64|riscv64)$ ]]; then
     export ART_TEST_VM_IMG="ubuntu-23.10-server-cloudimg-$TARGET_ARCH.img"