Video CI test on iOS device

[sauwming]

Video test on iOS device using Bitrise and Firebase.
Device testing with Firebase https://devcenter.bitrise.io/en/testing/device-testing-with-firebase.html

Test setup:

• Using ipjsua-swift sample app.
• Video capture: colorbar. Video renderer: Metal

Test scenario:

• Local video call utilising a single iOS device only (video call initiated to local account sip:localhost:5080).
  UI test (Automated): Simulate triple tap on Destination: text field, type in the text sip:localhost:5080. Verify using XCTAssert that the text is correct. If yes, click the button Make call.
• The device will only display one video, so only one party will transmit the video, while the other one will receive and show the video.
  Verification: Make sure that the incoming video view is not nil (i.e. check if pjsua_vid_win_info.hwnd.info.ios.window != NULL).

[nanangizz]

Add some description about the test scenarios & scope? E.g: on video call, check if video/colorbar appears/disappears at both sides.