[camera_android_camerax] use MediaSettings::fps for image preview, streaming, and video recording

[dasyad00]

Implements MediaSettings::fps in camera_android_camerax for image preview, image streaming, and video recording.

• Resolves #167719: implements the feature instead of adding documentation that it does not work.
• Partially resolves #176148: only implements for camera_android_camerax, and uses the existing MediaSettings::fps instead of adding parameters to CameraImageStreamOptions

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under¹.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under¹.
• I updated/added any relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under¹.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

Footnotes

1. Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩² ↩³

[camsim99]

This looks great! Thank you so much for taking this on. This will be a huge improvement to the plugin!

I think we need to add a Dart test, but otherwise LGTM. Let's get a second review.

[camsim99]

Nit: where you added this annotation, can you leave a comment as to why this is safe?

[camsim99]

I think we should add a test to make sure that if the fps media setting is passed, we actually set it as expected. I know these test are a bit daunting to write so let me know if you need help 😅

Just in case you need help getting started: The hardest part is mocking the pigeon calls. There are several other createCamera tests you can copy or modify to handle the mocks, though. But there are some helper methods at the top of the file that can help with that. I think you could end up doing something like

packages/packages/camera/camera_android_camerax/test/android_camera_camerax_test.dart

Lines 4649 to 4662 in 3404a0b

	newCameraSelector:
	({
	LensFacing? requireLensFacing,
	CameraInfo? cameraInfoForFilter,
	// ignore: non_constant_identifier_names
	BinaryMessenger? pigeon_binaryMessenger,
	// ignore: non_constant_identifier_names
	PigeonInstanceManager? pigeon_instanceManager,
	}) {
	if (cameraInfoForFilter == mockFrontCameraInfo) {
	return mockFrontCameraSelector;
	}
	return mockBackCameraSelector;
	},

where can check the fps and return a mock object then check that the use case (like camera.videoCapture) equals your mock object.

[bparrishMines]

LGTM pending unit tests and updating the lint-baseline.xml.

[bparrishMines]

This plugin updates [lint-baseline.xml] (https://github.com/flutter/packages/blob/main/packages/camera/camera_android_camerax/android/lint-baseline.xml) to handle this specific warning.

This should be updateable by following https://developer.android.com/studio/write/lint#snapshot in the example app. But this can be updated after getting both LGTMs.