Fix NPE when set ScaleType in xml. (#1433)

Fixes #1432
diff --git a/lottie/src/main/java/com/airbnb/lottie/LottieAnimationView.java b/lottie/src/main/java/com/airbnb/lottie/LottieAnimationView.java
index a8113d5..44b58bb 100644
--- a/lottie/src/main/java/com/airbnb/lottie/LottieAnimationView.java
+++ b/lottie/src/main/java/com/airbnb/lottie/LottieAnimationView.java
@@ -204,6 +204,9 @@
       setRenderMode(RenderMode.values()[renderModeOrdinal]);
     }
 
+    if (getScaleType() != null) {
+      lottieDrawable.setScaleType(getScaleType());
+    }
     ta.recycle();
 
     lottieDrawable.setSystemAnimationsAreEnabled(Utils.getAnimationScale(getContext()) != 0f);
@@ -844,7 +847,9 @@
 
   @Override public void setScaleType(ScaleType scaleType) {
     super.setScaleType(scaleType);
-    lottieDrawable.setScaleType(scaleType);
+    if (lottieDrawable != null) {
+      lottieDrawable.setScaleType(scaleType);
+    }
   }
 
   @MainThread