[Blogging Prompts] Add remote field to Social FF and enable it

[thomashorta]

Fixes #18264

Sets a remote feature flag called blogging_prompts_social_enabled and sets the local default value of the BloggingPromptsSocialFeatureConfig flag to true.

I am using the "Not Ready for Merge" tag while I confirm if we need to add a message to the release notes.

To test:

1. Install and open an older Jetpack app version (such as this one)
2. Login with a WP.com account
3. Select a blogging site (has at least a few posts)
4. Verify the Prompts card is shown in the dashboard
5. Verify it shows the number of answers and that is not clickable
6. Install and open the Jetpack app from this PR
7. Do steps 2-3 if needed
8. Verify the Prompts card is shown in the dashboard
9. Verify it shows a "View all responses" action
10. Tap the "View all responses" button
11. Verify it takes you to the topic screen for that prompt

Regression Notes

1. Potential unintended areas of impact
   N/A

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   N/A

3. What automated tests I added (or what prevented me from doing so)
   N/A just FF update.

PR submission checklist:

• I have completed the Regression Notes.
• 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.

[wpmobilebot]

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

	App Name	Jetpack
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr18265-2d20793
	Commit	2d20793
	Direct Download	jetpack-prototype-build-pr18265-2d20793.apk

Note: Google Login is not supported on these builds.

[wpmobilebot]

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

	App Name	WordPress
	Flavor	Jalapeno
	Build Type	Debug
	Version	pr18265-2d20793
	Commit	2d20793
	Direct Download	wordpress-prototype-build-pr18265-2d20793.apk

Note: Google Login is not supported on these builds.

[RenanLukas]

Thanks for the changes, @thomashorta . It's working as expected.

LGTM