fix: clear progress bar width after animation is completed

[ferenchuk]

Sets bar width to 0 when animation is completed. It prevents full-width progress bar blinking after new animation call.
Steps to reproduce bug:

1. Go to demo page and click "Real Example".
2. Set debugger Here
   if (includeBar) { $animate.enter(loadingBarContainer, $parent); }
3. Click "Real Example" again and check loadingBarContainer's childNode styles. Here will be width:100%. Also you will see progress bar with full width.

Browser: Any