added_barrier_dissmissable_pagebuilder_to_customtransitionpage

[ismailfarisi]

✨ What kind of change does this PR introduce? (Bug fix, feature, docs update...)

The barrierdissmissable property of customtransitionpage was not working. this bug is fixed also introduced pageBuilder instead of child in customTransitionPage which gives more control for animation

⤵️ What is the current behavior?

the dialog is not dissmissing after touching outside screen after making the barrierdissmissable property of customtransitionpage to true

Also the child property of CustomTransitionPage dosent give more control over animation

🆕 What is the new behavior (if this is a feature change)?

making the barrierDismmissable property to true makes the dialog dissmissable after pressing outside

more control over animation

💥 Does this PR introduce a breaking change?

no

🐛 Recommendations for testing

yes

📝 Links to relevant issues/docs

🤔 Checklist before submitting

• [yes ] I made sure all projects build.
• [ no] I updated CHANGELOG.md to add a description of the change.
• [no ] I updated the relevant documentation.
• [ yes] I updated the relevant code example.
• [ no] I rebased onto current master.

[csells]

@ismailfarisi I'm curious why you marked this as not a breaking change. Doesn't everyone that's using CustomTransitionPage today need to move from a child to a pageBuilder?

[ismailfarisi]

actually, I'm new to contributing
all the tests were passed in my local test. I believe the failed test might be the public_member_api_docs, so can i put ignore error annotation , Or is there any other way?

[chunhtai]

Since this package has been moved to https://github.com/flutter/packages/tree/main/packages/go_router

Can you create a pull request against the flutter/packages instead?