feat(alert): update styles to iOS 17 specs (#28726)

Issue number: N/A

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## What is the current behavior?
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Alerts don't match the iOS 17 spec for styling.

## What is the new behavior?
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this PR. -->

- Overlay border radius increased.
- Input font size increased.
- Input padding increased.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

The difference in the MD screenshots is the box shadow on the header in
the background. This was a change made a while back that probably wasn't
caught due to the pixel threshold on the screenshot update job. Deleting
all screenshots and running again got it updated.

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Co-authored-by: ionitron <hi@ionicframework.com>
Co-authored-by: Liam DeBeasi <liamdebeasi@users.noreply.github.com>

core/src/components/alert/alert.ios.scss

@@ -95,6 +95,8 @@
   background-color: $alert-ios-input-background-color;
   appearance: none;
 
+  font-size: dynamic-font(16px);
+
   &::placeholder {
     color: $alert-ios-input-placeholder-color;
 

core/src/components/alert/alert.ios.vars.scss

@@ -99,7 +99,7 @@ $alert-ios-content-max-height:                          240px !default;
 $alert-ios-input-margin-top:                            10px !default;
 
 /// @prop - Padding top on the alert input
-$alert-ios-input-padding-top:                           6px !default;
+$alert-ios-input-padding-top:                           7px !default;
 
 /// @prop - Padding end on the alert input
 $alert-ios-input-padding-end:                           $alert-ios-input-padding-top !default;
@@ -120,7 +120,7 @@ $alert-ios-input-border-color:                          $background-color-step-2
 $alert-ios-input-border:                                $hairlines-width solid $alert-ios-input-border-color !default;
 
 /// @prop - Border radius of the alert input
-$alert-ios-input-border-radius:                         4px !default;
+$alert-ios-input-border-radius:                         7px !default;
 
 /// @prop - Background color of the alert input
 $alert-ios-input-background-color:                      $background-color !default;