IMS-VT: Import zoom control bar source code and resources

- Add zoom control widget and resources

IMS-VT: Adding zoom widget to the video call UI

- Add zoom control and zoom control bar in UI. Add
  resource files for zoom slider, zoom in, alert dialog, etc

- Toggle zoom control when user clicks on camera preview

CRs-Fixed: 767934

IMS-VT: Catch the exception when dismissing the zoom alert dialog

- When we dismiss the zoom alert dialog, any exception caused
  should not crash the phone process

- Catch any exception that occurs when dismissing the zoom alert
  dialog and log it instead of letting it crash phone process

Change-Id: Ib0664d080814273e8135e04662b5e8595bbbba93
CRs-Fixed: 938992