Support elevation correctly (#305)

Author: Cameron Mace

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/Utils.java

@@ -54,12 +54,14 @@ static Bitmap getBitmapFromDrawable(Drawable drawable) {
   }
 
   static Bitmap generateShadow(Drawable drawable, float elevation) {
-    int widthHeight = toEven(10 * (elevation == 0 ? 1 : elevation));
-    Bitmap bitmap = Bitmap.createBitmap(widthHeight, widthHeight,
-      Bitmap.Config.ARGB_8888);
+    int width = drawable.getIntrinsicWidth();
+    int height = drawable.getIntrinsicHeight();
+    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
     Canvas canvas = new Canvas(bitmap);
     drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
     drawable.draw(canvas);
+    bitmap = Bitmap.createScaledBitmap(bitmap,
+      toEven(width + elevation), toEven(height + elevation), false);
     return bitmap;
   }
 

plugin-locationlayer/src/main/res/drawable/mapbox_user_icon_shadow.xml

@@ -1,17 +1,19 @@
-<?xml version="1.0" encoding="utf-8"?>
 <layer-list
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:opacity="opaque">
   <item
     android:gravity="center">
     <shape
-      android:shape="rectangle">
+      android:shape="oval">
+      <size
+        android:width="22dp"
+        android:height="22dp"/>
       <gradient
+        android:centerColor="#40000000"
         android:endColor="#00000000"
-        android:gradientRadius="57.5"
-        android:startColor="#59000000"
-        android:type="radial">
-      </gradient>
+        android:gradientRadius="11dp"
+        android:startColor="#40000000"
+        android:type="radial"/>
     </shape>
   </item>
 </layer-list>