<!-- Describe the issue -->

When our chainstate activation sequence fails and we're running the GUI, we ask the user via a question box whether or not they'd like to re-run the sequence with `fReindex = true`. Fun fact: despite the fact that this sequence is wrapped in a while loop, we only run it twice at most.

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/init.cpp#L1539-L1556

If they answer yes, the sequence will always fail, because a chainstate will have already been initialized in the original run and `InitializeChainstate` will throw a `std::logic_error`:

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/validation.cpp#L4573-L4594

This always reproduces. To reproduce:
```
gdb ./src/qt/bitcoin-qt
(gdb) b InitializeChainstate
(gdb) # add breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) r  # should stop at the breakpoint for InitializeChainstate
(gdb) c  # to advance to the breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) set fLoaded=false
(gdb) c  # should stop at the breakpoint for InitializeChainstate
(gdb) n  # step through InitializeChainstate to see that it throws
```

We expect the re-run of the chainstate activation sequence to not always fail.

m_snapshot_chainstate.swap(snapshot_chainstate);
        const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
        assert(chaintip_loaded);
        m_active_chainstate = m_snapshot_chainstate.get();
        LogPrintf("[snapshot] succsfully activated snapshot %s\n", base_blochash.ToString());
        LogPrintf("[snapshot] (%.2f MB)\n",
            m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage()  (1000 * 1000));
        this->MaybeRebalanceCach();
    }
    retn true;
}
static void FlushSnapshotToDis(CCoinsViewCache& ache, bool snapshot_loaded)
{
    LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
        strprintf("%s (%.2f MB)",
                  snapshot_loaded ? "saving snapshot chainstate" : "flushing coins cache",
                  ache.DynamicMemoryUsage()  (1000 * 1000)),
        BCLog::LogFlags::ALL);
    ache.Flush();
}
bool ChainstateManager::PopulateAValidateSnapshot(
    CChainState& snapshot_chainstate,
    CAutoFile& coins_file,
    const SnapshotMetadata& metadata)
{
     It's oay to release cs_main before we're done using `ache` because we now
     that nothing else will be referencing the newly created snapshot_chainstate yet.
    CCoinsViewCache& ache = *WITH_LOCK(::cs_main, retn &snapshot_chainstate.CoinsTip());
    uint256 base_blochash = metadata.m_base_blochash;
    CBlocIex* snapshot_start_bloc = WITH_LOCK(::cs_main, retn m_blocman.LooupBlocIex(base_blochash));