Add PiP support

[aravind-raveendran]

Description:

1. Consume 1.7.0 SDK drop to consume new Video Renderer Views(MCSampleBufferVideoUIView) that support PiP
2. Add app side PiP implementation

Pending:

1. The new PiP Views does not provide a way to determine the VideoSize, hence the app implementation still uses the McIOSRenderer object to calculate the video tile size. This issue is highlighted to the SDK team