[video_player] Separate texture ID on Android

[stuartmorgan-g]

Cleans up the tech debt of having two different methods of generating player IDs on Andoird, as was recently done on iOS. The current code was a result of adding non-texture-based players without refactoring the Dart<->Java communication, and relied on knowing that the engine assigned texture IDs by increasing an incrementing value. This fully separates texture IDs from player IDs, so that the plugin can fully control player ID management without relying on engine internals.

This also brings the Android and iOS implementations into better alignment, so that they don't have differences that aren't related to the platforms themselves.

Follow-up to work done for flutter/flutter#86613 Prep for flutter/flutter#172763

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
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• I read and followed the relevant style guides and ran the auto-formatter.
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• 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.
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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

[gemini-code-assist]

Code Review

This pull request is a well-executed refactoring of the Android video player implementation. It successfully decouples player IDs from texture IDs by introducing separate creation methods for platform views and texture views in the Pigeon API. This change simplifies the logic, removes technical debt, and brings the Android code into closer alignment with the iOS implementation. The refactoring is consistently applied across the native Java code, Dart plugin code, and tests, resulting in a cleaner and more maintainable codebase.

[gemini-code-assist]

The current changelog entry is a bit generic. To better inform developers about this significant and beneficial refactoring, consider making the description more specific. A more descriptive entry will help users quickly understand the value of this update.

Suggested change

	* Restructures internal logic for player creation and tracking.
	* Separates player IDs from texture IDs on Android, simplifying internal player creation and tracking.