Added the custom dialog windowBackground back (fix permission dialogs)

app/src/main/res/drawable/default_dialog_background.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+
+    <solid android:color="?attr/dialog_background_color" />
+
+    <corners android:radius="?dialogCornerRadius" />
+
+</shape>

app/src/main/res/values/styles.xml

@@ -23,6 +23,7 @@
     </style>
 
     <style name="ThemeOverlay.Session.AlertDialog" parent="ThemeOverlay.AppCompat.Dialog.Alert">
+        <item name="android:windowBackground">@drawable/default_dialog_background</item>
         <item name="android:colorBackground">?attr/dialog_background_color</item>
         <item name="dialog_background_color">?colorPrimary</item>
         <item name="android:colorBackgroundFloating">?colorPrimary</item>

app/src/main/res/values/themes.xml

@@ -248,7 +248,7 @@
     </style>
 
     <style name="Theme.TextSecure.Dialog.MediaSendProgress" parent="@android:style/Theme.Dialog">
-        <item name="android:colorBackground">?attr/dialog_background_color</item>
+        <item name="android:background">@drawable/default_dialog_background</item>
         <item name="android:windowNoTitle">true</item>
     </style>