Update tooltip text for all "locked" default rules

[JmillsExpensify]

Default rules can't be deleted, so we've disabled the row checkbox and added a lock icon instead. The current lock icon say Deleted which is a bit terse. Let's update to Default rules cannot be deleted

Issue Owner

Current Issue Owner: @situchan

[JmillsExpensify]

In the queue

[melvin-bot]

This issue has not been updated in over 15 days. @JmillsExpensify, @JS00001, @Krishna2323, @situchan, @dubielzyk-expensify eroding to Monthly issue.

P.S. Is everyone reading this sure this is really a near-term priority? Be brave: if you disagree, go ahead and close it out. If someone disagrees, they'll reopen it, and if they don't: one less thing to do!