fix(ios, md): double tapping back button no longer causes app to go back 2 pages

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: resolves #18455

What is the new behavior?

• Remove pointer events from entering and leaving views when transition starts and clear them when transition ends
• This does not impact swipe to go back because that gesture happens on ion-router-outlet, and pointer events are being removed deeper in the DOM tree, so router outlet still receives pointer events.

Does this introduce a breaking change?

• Yes
• No

Other information