docs: Document settings related to UIAutomator2 mjpeg [screen] streaming feature + cleanup (#14203)
docs: Document settings related to UIAutomator2 mjpeg [screen] streaming feature + cleanup (#14203)

* Document settings related to UIAutomator2 mjpeg [screen] streaming feature + cleanup

* Incorporating code-review feedback
appium/appium,appium/appium,appium/appium,appium/appium,appium/appium,appium/appium