fix(windows): fix crash in GetCellularGeneration for some LTE network adapters

[aironefr]

Overview

Some users are facing this crash: 0xC0000005: Access violation reading location 0x0000000000000000.
When inspecting crash dump, last stack trace in RNCNetInfo is RNCNetInfo.cpp:62

Root cause

These impacted users had LTE network adapter cards marked as LteAdvanced | Custom which isn't support by current RNCNetInfo implementation as dataClass wasn't treated as an enum supporting flags.

So nullptr was assigned to std::optional<std::string> and since the optional object is considered initialized when assigning nullptr then when dereferencing the value, it led to null pointer exception.

Fix

• Use std::nullopt instead of nullptr for unknown class types.
• Don't use switch but use bitwise comparison to detect class type

Crash

Test Plan

Quickly reproed the crash then verified std::nullopt works.
We already applied this patch to our application and rolled it out to our users who validated the fix.

[mikehardy]

I'm not sure I like the change from switch/case to if/else if/else (just aesthetically - but if it's functional okay), but I love people that post PRs that contain triaged bug fixes and code working in production. Thank you!

[matt-oakes]

🎉 This PR is included in version 9.3.8 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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