update sdk version to 3.14.0

[video_call]: fix build on latest flutter versions

[audio_call]: fix build on latest flutter versions

Merge remote-tracking branch 'origin/connection_node'

[audio_call]: fix mute and hold actions

[video_call]: add connection node selection on login screen

[audio_call]: add connection node selection on login screen

Migrate from imperative apply of gradle plugins

Update iOS builds for flutter 3.19

[video_call] - update flutter version and dependencies

[video_call]: fix app name on login screen

[video_call}: update android code for null safety

[video_call}: update dart and iOS code for null safety

[audio_call]: remove setting remoteHandler to CXCallUpdate for Siri call announcement

Merge remote-tracking branch 'origin/background_push_android'