IMS-VT: Display video call related user notification messages on UI

- Display video quality changed indication to the user when
  it changes

- Display player state indication to user when player/camera
  status changes (video starts/stops or camera is not ready/failing)

- Display data usage changed to the user when call ends

IMS-VT: Remove call id from call substate/quality toast mesaages

- Remove call id from the toast messages as it's incorrect. Since
  we are displaying toasts only for the primary call, we are good

- Change the resource strings accordingly

IMS: Control display of player, video quality, data usage toasts.

Add configuration flags to control the display of player
start/stop, video quality and data usage toasts during VT Call.

IMS-VT: Detect call substate changes and notify the message controller

- Add a listener for listening to call details changed and parse the
  extras for detecting changes in call substate

- Once call substate change is detected, notify the InCall message
  controller which displays a Toast.

- Add a new qtistrings.xml file for all Qti strings. Add call substate
  string resources in it.

Change-Id: I02b62dff707ae7ad5c8ba5e03d1b238fef7459cf