add mute button and functionality for call notification + new button icons

src/components/ble/AlertNotificationService.cpp

@@ -118,3 +118,16 @@ void AlertNotificationService::RejectIncomingCall() {
 
   ble_gattc_notify_custom(connectionHandle, eventHandle, om);
 }
+
+void AlertNotificationService::MuteIncomingCall() {
+  auto response = IncomingCallResponses::Mute;
+  auto *om = ble_hs_mbuf_from_flat(&response, 1);
+
+  uint16_t connectionHandle = systemTask.nimble().connHandle();
+
+  if (connectionHandle == 0 || connectionHandle == BLE_HS_CONN_HANDLE_NONE) {
+    return;
+  }
+
+  ble_gattc_notify_custom(connectionHandle, eventHandle, om);
+}

src/components/ble/AlertNotificationService.h

@@ -29,10 +29,12 @@ namespace Pinetime {
 
         void AcceptIncomingCall();
         void RejectIncomingCall();
+        void MuteIncomingCall();
 
         enum class IncomingCallResponses : uint8_t {
           Reject = 0x00,
-          Answer = 0x01
+          Answer = 0x01,
+          Mute = 0x02
         };
 
       private: