[Android] Add breaking change docs for setting flags via the CLI in release mode

[camsim99]

Description of what this PR is changing or adding, and why:
Adds breaking change docs for restricting setting engine configuration flags on the command line when running a Flutter Android app in release mode with a prebuilt binary, i.e. flutter run --release --use-application-binary.

Issues fixed by this PR (if any):
Part of flutter/flutter#190461

PRs or commits this PR depends on (if any):
flutter/flutter#190870

Presubmit checklist

• If you are unwilling, or unable, to sign the CLA, even for a tiny, one-word PR, please file an issue instead of a PR.
• If this PR is not meant to land until a future stable release, mark it as draft with an explanation.
• This PR follows the Google Developer Documentation Style Guidelines—for example, it doesn't use i.e. or e.g., and it avoids I and we (first-person pronouns).
• This PR uses semantic line breaks
  of 80 characters or fewer.

[flutter-website-bot]

Staged preview of the updated flutter.dev site (updated for commit cea72ce):

https://flutter-dev-230821--www-pr13796-cli-bc-bza14d47.web.app

[sfshaza2]

This looks great, @camsim99! Please don't forget to add it to the index file.

[gemini-code-assist]

Code Review

This pull request adds a new documentation page explaining a breaking change that restricts command-line flags on prebuilt Android release binaries. Feedback on the documentation suggests correcting the highlighted line range in the XML code block to exclude the unrelated <activity> tag, and removing or replacing a Google-internal shortlink with a public reference.

[gemini-code-assist]

The highlightLines range is set to 6-13. However, line 13 of the code block is <activity>, which is not part of the metadata configuration being demonstrated. The metadata configuration ends on line 12 (android:value="false" />).

Consider updating the range to 6-12 to avoid highlighting unrelated code:

```xml title="AndroidManifest.xml" highlightLines=6-12

[gemini-code-assist]

This link points to a Google-internal URL (goto.google.com / go/ shortlink) which is not accessible to the general public. Since this is public-facing documentation, please remove this link or replace it with a link to a public design document or GitHub issue if one exists.

[flutter-website-bot]

Staged preview of the updated docs.flutter.dev site (updated for commit cea72ce):

https://flutter-docs-prod--docs-pr13796-cli-bc-9xazfynb.web.app