fix(AppIcon): Use app icon consistent with Talk

AppIcon.icon/icon.json

@@ -1,18 +1,31 @@
 {
   "fill" : {
-    "solid" : "display-p3:0.10980,0.68627,1.00000,1.00000"
+    "linear-gradient" : [
+      "display-p3:0.10980,0.68627,1.00000,1.00000",
+      "srgb:0.00000,0.50980,0.78824,1.00000"
+    ],
+    "orientation" : {
+      "start" : {
+        "x" : 0.5,
+        "y" : 0
+      },
+      "stop" : {
+        "x" : 0.5,
+        "y" : 0.7
+      }
+    }
   },
   "groups" : [
     {
       "layers" : [
         {
-          "image-name" : "eraser.svg",
-          "name" : "eraser",
+          "image-name" : "Notes-white-1.svg",
+          "name" : "Notes-white-1",
           "position" : {
-            "scale" : 35,
+            "scale" : 30,
             "translation-in-points" : [
-              0,
-              0
+              13,
+              -14
             ]
           }
         }
@@ -29,18 +42,17 @@
     {
       "layers" : [
         {
-          "image-name" : "pencil.svg",
-          "name" : "pencil",
+          "image-name" : "Notes-white-2.svg",
+          "name" : "Notes-white-2",
           "position" : {
-            "scale" : 35,
+            "scale" : 30,
             "translation-in-points" : [
-              0,
-              0
+              13,
+              -14
             ]
           }
         }
       ],
-      "lighting" : "individual",
       "shadow" : {
         "kind" : "neutral",
         "opacity" : 0.5