Tweak icons to better blend with Android and iOS (#962)

* Add shadow to Android icon

* Add gradient to iOS icon

src/Android/Resources/drawable/ic_launcher_foreground.xml

@@ -1,13 +1,33 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
     android:width="108dp"
     android:height="108dp"
-    android:viewportWidth="1024.4897"
-    android:viewportHeight="1024.4897">
-  <group android:translateX="300.2449"
-      android:translateY="261.2449">
-    <path
-        android:pathData="M393.4,52.2C389.7,48.5 385.3,46.6 380.3,46.6L43.7,46.6C38.6,46.6 34.3,48.5 30.6,52.2C26.9,55.9 25,60.2 25,65.3L25,289.7C25,306.4 28.3,323.1 34.8,339.5C41.3,356 49.4,370.6 59.1,383.3C68.7,396.1 80.2,408.5 93.6,420.5C106.9,432.6 119.3,442.6 130.6,450.6C141.9,458.6 153.7,466.1 166,473.2C178.3,480.3 187,485.1 192.2,487.7C197.4,490.2 201.5,492.2 204.6,493.5C206.9,494.7 209.5,495.3 212.2,495.3C214.9,495.3 217.5,494.7 219.8,493.5C222.9,492.1 227.1,490.2 232.2,487.7C237.4,485.2 246.1,480.3 258.4,473.2C270.7,466.1 282.5,458.5 293.8,450.6C305.1,442.6 317.4,432.6 330.8,420.5C344.1,408.4 355.6,396 365.3,383.3C374.9,370.5 383,355.9 389.5,339.5C396,323 399.3,306.4 399.3,289.7L399.3,65.3C399,60.2 397.1,55.9 393.4,52.2ZM350,291.8C350,373 212,443 212,443L212,94.6L350,94.6L350,291.8Z"
-        android:fillColor="#ffffff"
-        android:fillType="nonZero"/>
-  </group>
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <group
+        android:scaleX="0.099"
+        android:scaleY="0.099"
+        android:translateX="24.3"
+        android:translateY="24.3">
+        <path android:pathData="M482,103l418,418l-235,434l-495,-495l130,75l175,-175z">
+            <aapt:attr name="android:fillColor">
+                <gradient
+                    android:endX="573.9931"
+                    android:endY="815.5847"
+                    android:startX="57.80515"
+                    android:startY="213.12973"
+                    android:type="linear">
+                    <item
+                        android:color="#3F000000"
+                        android:offset="0" />
+                    <item
+                        android:color="#00000000"
+                        android:offset="1" />
+                </gradient>
+            </aapt:attr>
+        </path>
+        <path
+            android:fillColor="#ffffff"
+            android:pathData="M481.4,102.2c-3.7,-3.7 -8.1,-5.6 -13.1,-5.6L131.7,96.6c-5.1,0 -9.4,1.9 -13.1,5.6C114.9,105.9 113,110.2 113,115.3v224.4c0,16.7 3.3,33.4 9.8,49.8c6.5,16.5 14.6,31.1 24.3,43.8c9.6,12.8 21.1,25.2 34.5,37.2c13.3,12.1 25.7,22.1 37,30.1c11.3,8 23.1,15.5 35.4,22.6c12.3,7.1 21,11.9 26.2,14.5c5.2,2.5 9.3,4.5 12.4,5.8c2.3,1.2 4.9,1.8 7.6,1.8c2.7,0 5.3,-0.6 7.6,-1.8c3.1,-1.4 7.3,-3.3 12.4,-5.8c5.2,-2.5 13.9,-7.4 26.2,-14.5c12.3,-7.1 24.1,-14.7 35.4,-22.6c11.3,-8 23.6,-18 37,-30.1c13.3,-12.1 24.8,-24.5 34.5,-37.2c9.6,-12.8 17.7,-27.4 24.2,-43.8c6.5,-16.5 9.8,-33.1 9.8,-49.8L487.3,115.3C487,110.2 485.1,105.9 481.4,102.2zM438,341.8C438,423 300,493 300,493L300,144.6h138C438,144.6 438,260.6 438,341.8z" />
+    </group>
 </vector>

src/Android/Resources/drawable/icon.xml

@@ -1,12 +1,30 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
     android:width="1024dp"
     android:height="1024dp"
     android:viewportWidth="1024"
     android:viewportHeight="1024">
-  <path
-      android:pathData="M1024,864c0,88.4 -71.6,160 -160,160H160C71.6,1024 0,952.4 0,864V160C0,71.6 71.6,0 160,0h704c88.4,0 160,71.6 160,160V864z"
-      android:fillColor="#175DDC"/>
-  <path
-      android:pathData="M829.8,128.6c-6.5,-6.5 -14.2,-9.7 -23,-9.7H217.2c-8.9,0 -16.5,3.2 -23,9.7c-6.5,6.5 -9.7,14.2 -9.7,23v393.1c0,29.3 5.7,58.4 17.1,87.3c11.4,28.8 25.6,54.4 42.5,76.8c16.9,22.3 37,44.1 60.4,65.3c23.4,21.2 45,38.7 64.7,52.7c19.8,14 40.4,27.2 61.9,39.7c21.5,12.5 36.8,20.9 45.8,25.3c9,4.4 16.3,7.9 21.7,10.2c4.1,2 8.5,3.1 13.3,3.1c4.8,0 9.2,-1 13.3,-3.1c5.5,-2.4 12.7,-5.8 21.8,-10.2c9,-4.4 24.3,-12.9 45.8,-25.3c21.5,-12.5 42.1,-25.7 61.9,-39.7c19.8,-14 41.4,-31.6 64.8,-52.7c23.4,-21.2 43.5,-42.9 60.4,-65.3c16.9,-22.4 31,-47.9 42.5,-76.8c11.4,-28.8 17.1,-57.9 17.1,-87.3V151.7C839.6,142.8 836.3,135.1 829.8,128.6zM753.8,548.4c0,142.3 -241.8,264.9 -241.8,264.9V203.1h241.8C753.8,203.1 753.8,406.1 753.8,548.4z"
-      android:fillColor="#FFFFFF"/>
+    <path
+        android:fillColor="#175DDC"
+        android:pathData="M1024,864c0,88.4 -71.6,160 -160,160H160C71.6,1024 0,952.4 0,864V160C0,71.6 71.6,0 160,0h704c88.4,0 160,71.6 160,160V864z" />
+    <path android:pathData="M803.2,195.8l668.8,668.8l-376,694.4l-792,-792l208,120l280,-280z">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="922.23486"
+                android:endY="1353.2649"
+                android:startX="96.33417"
+                android:startY="389.33688"
+                android:type="linear">
+                <item
+                    android:color="#3F000000"
+                    android:offset="0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#ffffff"
+        android:pathData="M802.24,194.52c-5.92,-5.92 -12.96,-8.96 -20.96,-8.96L242.72,185.56c-8.16,0 -15.04,3.04 -20.96,8.96C215.84,200.44 212.8,207.32 212.8,215.48l0,359.04c0,26.72 5.28,53.44 15.68,79.68c10.4,26.4 23.36,49.76 38.88,70.08c15.36,20.48 33.76,40.32 55.2,59.52c21.28,19.36 41.12,35.36 59.2,48.16c18.08,12.8 36.96,24.8 56.64,36.16c19.68,11.36 33.6,19.04 41.92,23.2c8.32,4 14.88,7.2 19.84,9.28c3.68,1.92 7.84,2.88 12.16,2.88c4.32,0 8.48,-0.96 12.16,-2.88c4.96,-2.24 11.68,-5.28 19.84,-9.28c8.32,-4 22.24,-11.84 41.92,-23.2c19.68,-11.36 38.56,-23.52 56.64,-36.16c18.08,-12.8 37.76,-28.8 59.2,-48.16c21.28,-19.36 39.68,-39.2 55.2,-59.52c15.36,-20.48 28.32,-43.84 38.72,-70.08c10.4,-26.4 15.68,-52.96 15.68,-79.68L811.68,215.48C811.2,207.32 808.16,200.44 802.24,194.52zM732.8,577.88C732.8,707.8 512,819.8 512,819.8L512,262.36l220.8,0C732.8,262.36 732.8,447.96 732.8,577.88z" />
 </vector>