add AccelerateInterpolator based on AOSP version

src/api-impl/android/view/animation/AccelerateInterpolator.java

@@ -0,0 +1,25 @@
+package android.view.animation;
+
+/**
+ * An interpolator where the rate of change starts out slowly and
+ * and then accelerates.
+ *
+ */
+public class AccelerateInterpolator implements Interpolator {
+	private final float mFactor;
+	private final double mDoubleFactor;
+
+	public AccelerateInterpolator() {
+		mFactor = 1.0f;
+		mDoubleFactor = 2.0;
+	}
+
+	public float getInterpolation(float input) {
+		if (mFactor == 1.0f) {
+			return input * input;
+		} else {
+			return (float)Math.pow(input, mDoubleFactor);
+		}
+	}
+
+}

src/api-impl/android/view/animation/Interpolator.java

@@ -0,0 +1,5 @@
+package android.view.animation;
+
+public interface Interpolator {
+	
+}

src/api-impl/meson.build

@@ -191,6 +191,8 @@ hax_jar = jar('hax', [
               	'android/util/TypedValue.java',
               	'android/util/Xml.java',
               	'android/util/XmlPullAttributes.java',
+              	'android/view/animation/AccelerateInterpolator.java',
+              	'android/view/animation/Interpolator.java',
               	'android/view/Choreographer.java',
               	'android/view/Display.java',
               	'android/view/Gravity.java',