fix(react): use custom animation when going back after a replace (#28674)

Issue number: resolves #28673

---------

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

When reviewing https://github.com/ionic-team/ionic-framework/pull/28671
I noticed a bug where the custom animation was not used when going back
after a replace.

`handleNavigate` will override whatever is in `incomingRouteParams`.
Since we were passing `routeAnimation` (which is `undefined`), it was
overriding the animation we set in `handleNavigateBack`.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- `routeAnimation` is no longer overridden

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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and migration path for existing applications below. -->


## Other information

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

Dev build: `7.6.1-dev.11702048520.13c82dad`

packages/react-router/src/ReactRouter/IonRouter.tsx

@@ -244,11 +244,17 @@ class IonRouterInner extends React.PureComponent<IonRouteProps, IonRouteState> {
     if (routeInfo && routeInfo.pushedByRoute) {
       const prevInfo = this.locationHistory.findLastLocation(routeInfo);
       if (prevInfo) {
+        /**
+         * This needs to be passed to handleNavigate
+         * otherwise incomingRouteParams.routeAnimation
+         * will be overridden.
+         */
+        const incomingAnimation = routeAnimation || routeInfo.routeAnimation;
         this.incomingRouteParams = {
           ...prevInfo,
           routeAction: 'pop',
           routeDirection: 'back',
-          routeAnimation: routeAnimation || routeInfo.routeAnimation,
+          routeAnimation: incomingAnimation,
         };
         if (
           routeInfo.lastPathname === routeInfo.pushedByRoute ||
@@ -270,7 +276,7 @@ class IonRouterInner extends React.PureComponent<IonRouteProps, IonRouteState> {
           const goBack = history.goBack || history.back;
           goBack();
         } else {
-          this.handleNavigate(prevInfo.pathname + (prevInfo.search || ''), 'pop', 'back', routeAnimation);
+          this.handleNavigate(prevInfo.pathname + (prevInfo.search || ''), 'pop', 'back', incomingAnimation);
         }
       } else {
         this.handleNavigate(defaultHref as string, 'pop', 'back', routeAnimation);