Make ActiveLabel as AccessibleElement by default.

[rozeridilar]

Set the label as accessible by default.

• When the voice over is active and there is more than one ActiveTypes, by default label selects the first activetype as accessible.
  Developers also can set the accessible active type:
  label.accessibleType = ActiveType
• The accessibility of label is true by default, to disable the accessibility of the label you should call: label.isAccessibilityEnabled = false