Rnmobile/vp native player caption

[jhnstn]

Adds the video caption to the native player.
The behavior follows the exiting React Native Video block:

• The caption is visible when the block is selected.
• The caption is always displayed regardless of the block settings *

• Note: On the web, the caption is removed and reset when clicking the "remove caption" toggle

Part of wordpress-mobile/gutenberg-mobile#5509

Proposed changes:

• Adds the caption to the native player

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

N/A

Does this pull request change what data or activity we track or use?

No

Testing instructions:

Display

• Open the mobile editor
• Add or select a VideoPress block
• If the block does not have a caption, verify the "Add caption" is visible below the video.
• If the block has a caption, verify that the caption is displayed correctly below the video.
• Deselect the block
• Verify that the caption is no longer displayed

Syncing

• Open a post on the web with a VideoPress block
• Disable captions on the block and save the update
• Open the post on the mobile editor
• Select the block and verify that "Add caption" is displayed
• Add a caption to the video and save the update.
• Reload the post in the web
• Verify that the caption is displayed

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

• ✅ Include a description of your PR changes.
  
• ✅ All commits were linted before commit.
  
• 🔴 Add a "[Status]" label (In Progress, Needs Team Review, ...).
  
• ✅ Add testing instructions.
  
• ✅ Specify whether this PR includes any changes to data or privacy.
  
• ✅ Add changelog entries to affected projects
  

This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation 🤖

---

The e2e test report can be found here. Please note that it can take a few minutes after the e2e tests checks are complete for the report to be available.

---

Once your PR is ready for review, check one last time that all required checks (other than "Required review") appearing at the bottom of this PR are passing or skipped.
Then, add the "[Status] Needs Team review" label and ask someone from your team review the code.
Once you’ve done so, switch to the "[Status] Needs Review" label; someone from Jetpack Crew will then review this PR and merge it to be included in the next Jetpack release.