use volume off / volume on icons instead of bell for notifications

deltachat-ios/Assets.xcassets/ic_notifications_off.imageset/Contents.json

@@ -1,23 +0,0 @@
-{
-  "images" : [
-    {
-      "filename" : "bell-off-outline_white_1x.png",
-      "idiom" : "universal",
-      "scale" : "1x"
-    },
-    {
-      "filename" : "bell-off-outline_white_2x.png",
-      "idiom" : "universal",
-      "scale" : "2x"
-    },
-    {
-      "filename" : "bell-off-outline_white_3x.png",
-      "idiom" : "universal",
-      "scale" : "3x"
-    }
-  ],
-  "info" : {
-    "author" : "xcode",
-    "version" : 1
-  }
-}

deltachat-ios/Assets.xcassets/volume_off.imageset/Contents.json

@@ -1,17 +1,17 @@
 {
   "images" : [
     {
-      "filename" : "baseline_volume_off_white_24pt_1x.png",
+      "filename" : "volume-off_1x.png",
       "idiom" : "universal",
       "scale" : "1x"
     },
     {
-      "filename" : "baseline_volume_off_white_24pt_2x.png",
+      "filename" : "volume-off_2x.png",
       "idiom" : "universal",
       "scale" : "2x"
     },
     {
-      "filename" : "baseline_volume_off_white_24pt_3x.png",
+      "filename" : "volume-off_3x.png",
       "idiom" : "universal",
       "scale" : "3x"
     }

deltachat-ios/Assets.xcassets/ic_notifications_on.imageset/Contents.json → deltachat-ios/Assets.xcassets/volume_on.imageset/Contents.json

@@ -1,17 +1,17 @@
 {
   "images" : [
     {
-      "filename" : "bell-outline_white_1x.png",
+      "filename" : "volume-high_1x.png",
       "idiom" : "universal",
       "scale" : "1x"
     },
     {
-      "filename" : "bell-outline_white_2x.png",
+      "filename" : "volume-high_2x.png",
       "idiom" : "universal",
       "scale" : "2x"
     },
     {
-      "filename" : "bell-outline_white_3x.png",
+      "filename" : "volume-high_3x.png",
       "idiom" : "universal",
       "scale" : "3x"
     }

deltachat-ios/View/ContactDetailHeader.swift

@@ -63,11 +63,7 @@ class ContactDetailHeader: UIView {
         button.translatesAutoresizingMaskIntoConstraints = false
         button.addTarget(self, action: #selector(muteBtnTapped), for: .touchUpInside)
         button.backgroundColor = DcColors.profileCellBackgroundColor
-        if #available(iOS 13.0, *) {
-            button.setImage(UIImage(systemName: "bell")?.sd_tintedImage(with: .systemBlue), for: .normal)
-        } else {
-            button.setImage(UIImage(named: "ic_notifications_on")?.sd_tintedImage(with: .systemBlue), for: .normal)
-        }
+        button.setImage(UIImage(named: "volume_on")?.sd_tintedImage(with: .systemBlue), for: .normal)
         button.layer.cornerRadius = 16
         button.layer.borderColor = DcColors.colorDisabled.cgColor
         button.layer.borderWidth = 1
@@ -143,16 +139,10 @@ class ContactDetailHeader: UIView {
     }
 
     func setMuted(isMuted: Bool) {
-        if #available(iOS 13.0, *) {
-            muteButton.setImage(isMuted ? UIImage(systemName: "bell.slash")?.sd_tintedImage(with: .systemBlue) :
-                                    UIImage(systemName: "bell")?.sd_tintedImage(with: .systemBlue),
-                                for: .normal)
-        } else {
-            muteButton.setImage(isMuted ?
-                                UIImage(named: "ic_notifications_off")?.sd_tintedImage(with: .systemBlue) :
-                                    UIImage(named: "ic_notifications_on")?.sd_tintedImage(with: .systemBlue),
-                                for: .normal)
-        }
+        muteButton.setImage(isMuted ?
+                            UIImage(named: "volume_off")?.sd_tintedImage(with: .systemBlue) :
+                                UIImage(named: "volume_on")?.sd_tintedImage(with: .systemBlue),
+                            for: .normal)
     }
 
     func showMuteButton(show: Bool) {