[SkottieView] surface methods for  adding and removing listeners in SkottieView

Change-Id: Iaa97a5661269c9f725cf44f977fed12c3c994b31
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/375070
Reviewed-by: Stan Iliev <stani@google.com>
Commit-Queue: Stan Iliev <stani@google.com>
diff --git a/platform_tools/android/apps/skottie/skottielib/src/main/java/org/skia/skottie/SkottieView.java b/platform_tools/android/apps/skottie/skottielib/src/main/java/org/skia/skottie/SkottieView.java
index d19ee6a..7210436 100644
--- a/platform_tools/android/apps/skottie/skottielib/src/main/java/org/skia/skottie/SkottieView.java
+++ b/platform_tools/android/apps/skottie/skottielib/src/main/java/org/skia/skottie/SkottieView.java
@@ -7,6 +7,7 @@
 
 package org.skia.skottie;
 
+import android.animation.Animator;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Color;
@@ -163,6 +164,14 @@
         return mAnimation;
     }
 
+    public void removeListener(Animator.AnimatorListener listener) {
+        mAnimation.removeListener(listener);
+    }
+
+    public void addListener(Animator.AnimatorListener listener) {
+        mAnimation.addListener(listener);
+    }
+
     // progress: a float from 0 to 1 representing the percent into the animation
     public void seek(float progress) {
         if(mAnimation != null) {