public void runAnimation(View view) {
        mAnimator.cancel();
        mAnimator.setInterpolator(mVisualizer.getInterpolator());
        mAnimator.setDuration(mDuration);
        mAnimator.start();
    }
Called when the "Run" button is clicked. It cancels any running animation
and starts a new one with the values specified in the UI.
AnimationsInterpolatorPlayground/app/src/main/java/com/example/android/interpolatorplayground/MainActivity.java