Remove ODWReachability and iOS 11 macOS 10.14 code with EOL for those platforms

[denny-msft]

Started investigating the crash from #1370 and realized that ODWReachability should only be applicable for platforms below iOS 11 and macOS 10.14. However, a crash stack from an iOS 18 device clearly shows these classes being deallocated.

-[ODWReachability stopNotifier] ODWReachability.m:367
-[ODWReachability dealloc] ODWReachability.m:265
Microsoft::Applications::Events::PlatformAbstraction::NetworkInformation::~NetworkInformation() NetworkInformationImpl.mm:102

Seems like there was a bug where these reachability classes were being initialized without guarded availability checks (see NetworkInformation::SetupNetDetect:108) when they should only be used for lower platforms.

Regardless, given the EOL of these versions, this PR remove references to ODWReachability and fixes the crash.

Testing

Verified with build-ios.sh.

[lalitb]

@absaroj - Can you help with the review. thanks.

[lalitb]

We should handle scenario where nw_path_monitor_create fails, and return nil - may be rare scenario but under system resource exhaustion?

[lalitb]

This is existing code, so probably not blocker here.

[thomasameisel]

The API docs describe this return value as non-optional so it should never be nil - https://developer.apple.com/documentation/network/nw_path_monitor_create()

[thomasameisel]

I take that back, I checked the docs in Xcode and it does indeed look like this can be nil. I'm finding a hard time finding a reference to these docs online. Here's what it says:

/*!
 * @function nw_path_monitor_create
 *
 * @abstract
 *		Create a default path monitor, that will allow the enumeration of all available
 *		interfaces on the system.
 *
 * @result
 *		Returns an allocated nw_path_monitor_t object on success.
 *		Callers are responsible for deallocating using nw_release(obj) or [obj release].
 *		These objects support ARC.
 *		Returns NULL on failure. Fails due to invalid parameters.
 */
API_AVAILABLE(macos(10.14), ios(12.0), watchos(5.0), tvos(12.0))
NW_RETURNS_RETAINED nw_path_monitor_t
nw_path_monitor_create(void);

[lalitb]

One question: This change raises the minimum iOS version from 10.0 to 12.0. Are there any concerns about existing customer devices still running iOS 10/11, or is this acceptable given that Apple has long since ended support for these versions?

[thomasameisel]

One question: This change raises the minimum iOS version from 10.0 to 12.0. Are there any concerns about existing customer devices still running iOS 10/11, or is this acceptable given that Apple has long since ended support for these versions?

I can only speak for iOS Outlook, but our min version is 18.0.

[denny-msft]

One question: This change raises the minimum iOS version from 10.0 to 12.0. Are there any concerns about existing customer devices still running iOS 10/11, or is this acceptable given that Apple has long since ended support for these versions?

App Store apps are required to be built with Xcode 16 or later as of April 2025, and only supports iOS 15 or later, so we should be okay.