Greatly lower threshold for arm lock flags
This MR changes the tresholds for L1:DMT_XARM_LOCK
and L1:DMT_YARM_LOCK
from 4000 to 1000. After MR !11 (merged) was implemented, it was noticed that the relevant XARM transmon's stable operating value had further dropped below the new threshold of 4000. To address this, I'm greatly lowering the thresholds for both flags to reduce the risk of further drops impacting these flags. Such a low threshold mirrors what is set for the corresponding LHO flags.