Release v3.5.2-alpha

• Fix video recording bug

New apis:

• cameraId - String id of currently opened camera device
• cameraIdsForFacing - SortedSet of string ids of camera devices for selected facing
• nextCamera() - Open next camera in sequence of sorted camera ids for current facing

Updated apis:

• start(cameraId) - Start now accepts an optional string cameraId to manually select which camera id to open. If nothing passed, first (default system) camera will be opened for selected facing
• app:facing AND cameraView.facing - Both now accepts a new facing value external in xml and Modes.Facing.FACING_EXTERNAL for in code usage. This facing open any external camera available and falls back to Modes.Facing.FACING_BACK if there is no external camera