Sets or returns a Boolean
value indicating whether the parameter can be animated. For
example, this property determines whether an FCurve could influence the value of this
parameter over time. A string parameter can never be
animated.
Changing the capability flags only affects one particular instance
of the parameter.
Note: Setting this property is not undoable. If you want to change
the animatable capability and make it undoable, then use Parameter.SetCapabilityFlag.