Check for LEADING *after* waiting to be LEADING or FOLLOWING

[tylerkaraszewski]

Details

This fixes a bug noticed when investigating a fork.

If we attempt to start a command, but are not LEADING or FOLLOWING (see lines 783-796, the collapsed section between the changes) we wait until we are before doing anything.

However, we've performed the canWriteParallel before we wait for this state change, so we could have been SEARCHING before the wait, and LEADING after. This will cause canWriteParallel to be false when it should not be. This leads to commands running in the sync thread that do not need to.

This change moves the check for LEADING to after the state of the server has stabilized.

I don't believe this actually affects the fork that occurred, but it is a detriment to performance.

Fixed Issues

Fixes https://github.com/Expensify/Expensify/issues/384477

Tests

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Internal Testing Reminder: when changing bedrock, please compile auth against your new changes

[dangrous]

This makes enough sense to me based on the description provided, but I definitely defer to those with more bedrock knowledge since I have not really dealt with it at all before.