DIOS-6734: MulitChannels (DO NOT MERGE)

[sheiladoherty-dolby]

This is just a basic implementation of Multi-Channels. There are various features such as labels & persistence, that need to by firmed up should we want make this a part of the application.

• turn on Multi-Channels in the settings toggle
• toggling on Multi-Channel will change the LandingView to show the ChannelDetailInputView
• ChannelDetailInputView starts with just 2 sets of textfields. To add up to 4 sets, press the + button
• for ease of testing, the first 2 streams are currently pre-populated (but can be changed)
• if the textfields are empty, they will just be skipped

2 Channels:

3 Channels:

4 Channels:

ChannelGridView portrait with 4 channels:

ChannelGridView landscape with 4 channels: