Revert "Enable dithering on RippleDrawable"

This reverts commit 1cbfc3b00b.

Reason for revert: CL was no-op
Bug: 189281134
Change-Id: I2c70b51dd1d2f679a8310b1847675360ce415d35

graphics/java/android/graphics/drawable/RippleDrawable.java

@@ -1193,9 +1193,6 @@ public class RippleDrawable extends LayerDrawable {
             mRipplePaint = new Paint();
             mRipplePaint.setAntiAlias(true);
             mRipplePaint.setStyle(Paint.Style.FILL);
-            if (mState.mRippleStyle == STYLE_PATTERNED) {
-                mRipplePaint.setDither(true);
-            }
         }
 
         final float x = mHotspotBounds.exactCenterX();