CONVOSDK-4493: Fix slow reconnection after network switch or app foregrounding

[blackneck]

Fix slow reconnection after network switch or app foregrounding

Summary

Fixes issue where the SDK takes 28-30 seconds to reconnect after network changes (WiFi ↔ cellular) or when returning from background.

Problem

When the device's network changed, the SDK continued using exponential backoff from previous failed attempts, causing unnecessary 28-30 second delays.

Root Cause

1. No detection of default network changes - only tracked availability, not active network switches
2. Backoff not reset on network/foreground events in WaitAndReconnect state
3. No immediate reconnect trigger - waited for scheduled timeout

Solution

1. Default Network Change Detection (Android)

• Implemented registerDefaultNetworkCallback() to detect active network switches
• Added onDefaultNetworkChanged callback to ConnectivityMonitor

2. Reset Backoff on Network/App Events

In WaitAndReconnect state:

• OnDefaultNetworkChanged / OnAppForegrounded / OnConnect: Reset failedReconnectionAttempts = 0 and immediately transition to Connecting

3. Force Reconnect on Network Switch While Connected

• When default network changes while connected, force reconnect to use new network path

[blackneck]

this was not released yet

[blackneck]

same as sharedInternal - bumped but not actually released