leaudio/json: Add examples for Game and Recording context types

Note: For Game usecase, the priority is to open ISO channels along with
voice back channel. Then it is up to application to make use of it or
not.

Bug: 224933710
Test: atest --host bluetooth_le_audio_test
Sponsor: @jpawlowski
Change-Id: Ia0b94726e6ce375a6704ba171129114f1aefdfdd
(cherry picked from commit e831a14b)