title: Android animation slow down on activity transitions
body: <p>I have a FragmentDialog containing an animation composed by two ImageView that I animate indefinitely when App is doing some background work, in other words I use it as a loading dialog. ( I know that loading dialogs that block UI are bad practice in Android but I was forced to do it because I have to do an IOS porting).
  This animation is always smooth except during transitions between two activities. 
  Example : I have to do a login screen and the loading dialog animation must run continuously till the login activity is no more visible and the next activity takes its place.
  When the login is at the end , and transition between the two activity starts, the animation slow down and it's very jerky.
  I begin the animations with startAnimation(AnimationUtils.loadAnimation(context, R.anim.rotate)); on 2 ImageView.
  How can I solve this problem? Thanks in advance</p>