Summary:
Refines the condition for ignoring updates to an already-open redbox on iOS.
Previously we would only update the stack trace if the message string in the update was exactly the same as in the initial redbox. With this diff we rely on the `exceptionId` parameter instead, and only fall back to string comparison if it's omitted (i.e. for non-JS uses of redbox on iOS).
NOTE: `exceptionId` is part of the existing ExceptionsManager API and is already supported on Android.
Reviewed By: sammy-SC
Differential Revision: D17226179
fbshipit-source-id: 5940110bf4e4358a8a1b3477e8d2cf8b224dd9f8