Disable native shadows when compat shadows are always drawn.

PiperOrigin-RevId: 219134990

Author: cketcham

lib/java/com/google/android/material/shape/MaterialShapeDrawable.java

@@ -848,6 +848,11 @@ private void calculatePathForSize(RectF bounds, Path path) {
   @TargetApi(VERSION_CODES.LOLLIPOP)
   @Override
   public void getOutline(Outline outline) {
+    if (shadowCompatMode == SHADOW_COMPAT_MODE_ALWAYS) {
+      // Don't draw the native shadow if we're always rendering with compat shadow.
+      return;
+    }
+
     boolean isRoundRect = shapeAppearanceModel.isRoundRect();
 
     if (isRoundRect) {