Display last animated text value (#1689)

When using animated text, the last value was not shown. Issue can be reproduce with this json: https://assets7.lottiefiles.com/packages/lf20_fteywrno.json

Co-authored-by: Frantisek Nagy <frantisek.nagy@erstegroup.com>

lottie/src/main/java/com/airbnb/lottie/animation/keyframe/TextKeyframeAnimation.java

@@ -11,6 +11,9 @@ public TextKeyframeAnimation(List<Keyframe<DocumentData>> keyframes) {
   }
 
   @Override DocumentData getValue(Keyframe<DocumentData> keyframe, float keyframeProgress) {
-    return keyframe.startValue;
+    if (keyframeProgress != 1.0f || keyframe.endValue == null)
+      return keyframe.startValue;
+    else
+      return keyframe.endValue;
   }
 }