Respect safe area for "Reply to post" section on the Comments screen

[justtwago]

Fixes #22603

This PR fixes missing padding for the reply section on the Comments screen that ignored the safe area and was overlayed by the Home indicator.

RPReplay_Final1708452812.MP4

To test:

• Go to Reader -> Comments
• Make sure the Reply section respects the bottom safe area
• Tap on it to reveal the keyboard
• Make sure that the Reply section is visible above the keyboard

Regression Notes

1. Potential unintended areas of impact
   Comments screen.

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   Manual testing, UI tests.

3. What automated tests I added (or what prevented me from doing so)
   Automated tests already exist.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Testing checklist:

• WordPress.com sites and self-hosted Jetpack sites.
• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• VoiceOver.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• iPhone and iPad.
• Multi-tasking: Split view and Slide over. (iPad)

[dangermattic]

	1 Warning
⚠️	PR is not assigned to a milestone.

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📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr22628-d5e6dde
	Version	24.3
	Bundle ID	com.jetpack.alpha
	Commit	d5e6dde
	App Center Build	jetpack-installable-builds #7931

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[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr22628-d5e6dde
	Version	24.3
	Bundle ID	org.wordpress.alpha
	Commit	d5e6dde
	App Center Build	WPiOS - One-Offs #8901

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[salimbraksa]

[Nit] I think the property replyTextViewBottomConstraint is no longer needed, maybe it should be removed?

[justtwago]

Good catch! Thank you!

[salimbraksa]

Left one minor comment. LGTM! 🚀

[salimbraksa]

⚠️ I didn't know about this KeyboardDismissHelper earlier, but it does seem this type requires a bottomLayoutConstraint. But we cannot pass its own self.keyboardManager.bottomLayoutConstraint in the initializer. This can cause crashes and unexpected behavior at runtime:

• The property KeyboardDismissHelper.bottomLayoutConstraint is expecting a non-optional value.
• self.keyboardManager.bottomLayoutConstraint is not initialized yet, and code like this is not possible in Swift. So although this is allowed in Objective-C, weird behavior can occur at Runtime.

I suggest to bring back the self.replyTextViewBottomConstraint property and set it to:

self.replyTextViewBottomConstraint = [self.view.keyboardLayoutGuide.topAnchor constraintEqualToAnchor:self.replyTextView.bottomAnchor];

Then activate it alongside other constraints

[NSLayoutConstraint activateConstraints:@[
  [self.replyTextView.leadingAnchor constraintEqualToAnchor:self.replyTextView.leadingAnchor],
  [self.replyTextView.trailingAnchor constraintEqualToAnchor:self.replyTextView.trailingAnchor],
  self.replyTextViewBottomConstraint
]];

[justtwago]

Makes sense! 💯 Tested this approach and it works slightly incorrectly because we reuse the same constraint in a few places.

Instead of that I reverted the replyTextViewBottomConstraint for the keyboard manager only.