Set correct frame when animation ends and speed is < 0 (#1222)

Fixes #1207
diff --git a/lottie/src/main/java/com/airbnb/lottie/utils/LottieValueAnimator.java b/lottie/src/main/java/com/airbnb/lottie/utils/LottieValueAnimator.java
index 7898461..7318f55 100644
--- a/lottie/src/main/java/com/airbnb/lottie/utils/LottieValueAnimator.java
+++ b/lottie/src/main/java/com/airbnb/lottie/utils/LottieValueAnimator.java
@@ -96,7 +96,7 @@
     notifyUpdate();
     if (ended) {
       if (getRepeatCount() != INFINITE && repeatCount >= getRepeatCount()) {
-        frame = getMaxFrame();
+        frame = speed < 0 ? getMinFrame() : getMaxFrame();
         removeFrameCallback();
         notifyEnd(isReversed());
       } else {