v3: Modal lost response when modal was over an alert and it only happened on device

[ionitron-bot]

Original issue by @qiluo on 2018-07-04T02:16:48Z

Ionic version: (check one with "x")
(For Ionic 1.x issues, please use https://github.com/ionic-team/ionic-v1)
[ ] 2.x
[x] 3.x
[ ] 4.x

I'm submitting a ... (check one with "x")
[x] bug report
[ ] feature request

Current behavior:

In my app, there were an alert and a modal, depends on http response, the alert and the modal displayed in random sequence. Only when modal displayed over the alert and only on the device, the modal lost response, user clicked the modal content and no response. If on Chrome simulator, everything was ok

Expected behavior:

No matter modal over alert or alert over modal, the user interaction should properly work

Steps to reproduce:

Related code:

insert short code snippets here

Other information:

Ionic info: (run ionic info from a terminal/cmd prompt and paste output below):

cli packages: 

    @ionic/cli-utils  : 1.19.2
    ionic (Ionic CLI) : 3.20.0

global packages:

    cordova (Cordova CLI) : 8.0.0

local packages:

    @ionic/app-scripts : 3.1.6
    Cordova Platforms  : ios 4.5.4
    Ionic Framework    : ionic-angular 3.9.2
System:

    ios-deploy : 1.9.2
    ios-sim    : 6.0.0
    Node       : v8.4.0
    npm        : 6.1.0
    OS         : macOS Sierra
    Xcode      : Xcode 9.2 Build version 9C40b