bug: ios, two finger swipe up gesture not working in standalone app/pwa

# Bug Report

**Ionic version:**

[ ] **4.x**
[x] **5.x**

**Current behavior:**
"Two-finger swipe up" when voiceover is on in iOS app, should "Speak the entire screen from the top" at the moment voiceover does not read anything from the top. voiceover gesture can be found [here](https://support.apple.com/en-in/guide/iphone/iph3e2e2281/ios)

**Expected behavior:**
"Two-finger swipe up" when voiceover is on should read everything on screen from the top in iOS.

**Steps to reproduce:**
1) open the ionic app in iOS device
2) turn on VoiceOver
3) and do a "Two-finger swipe up"

you'll notice that, Voice over does not read anything from the top. however one thing to notice is that, when "Two-finger swipe down" voice over should "Speak the entire screen from the selected item" is working.

Let me know if more information is needed to reproduce.

Thanks

Start by reproducing the issue in an Ionic standalone app or PWA on an iOS device with VoiceOver enabled, following the listed two-finger swipe steps. Investigate the platform gesture behavior and compare it with the working two-finger swipe down gesture. Done means the swipe up gesture reads the entire screen from the top while the existing behavior remains intact.

索引モデルが issue の本文から書いたものです。