Replaced the PDF preview icons with explicit PNG ones (smaller size, better rendering)

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-Calculator-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-Calculator-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-Calculator-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-Calculator-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-Calculator-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-Meeting-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-Meeting-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-Meeting-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-Meeting-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-Meeting-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-News-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-News-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-News-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-News-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-News-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-Notes-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-Notes-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-Notes-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-Notes-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-Notes-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-Stocks-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-Stocks-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-Stocks-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-Stocks-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-Stocks-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {

Session/Meta/Images.xcassets/AppIconPreviews/AppIcon-Weather-Preview.imageset/Contents.json

@@ -1,8 +1,19 @@
 {
   "images" : [
     {
-      "filename" : "AppIcon-Weather-Preview.pdf",
-      "idiom" : "universal"
+      "filename" : "AppIcon-Weather-Preview.png",
+      "idiom" : "universal",
+      "scale" : "1x"
+    },
+    {
+      "filename" : "AppIcon-Weather-Preview@2x.png",
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "filename" : "AppIcon-Weather-Preview@3x.png",
+      "idiom" : "universal",
+      "scale" : "3x"
     }
   ],
   "info" : {