feat(Android): update getting started and feature pages

[kahest]

DESCRIBE YOUR PR

Updates Android getting started page to use new product selector.

This also includes several smaller improvements to streamline the page and the navigation:

• move recent feature highlights to features page
• remove some superfluous/old notes that are not important enough any more to call out on the first landing page
• move some callouts and new items to next steps section
• refactor file structure so that there's no platform-includes anymore

IS YOUR CHANGE URGENT?

Help us prioritize incoming PRs by letting us know when the change needs to go live.

• ideally June 11, latest June 20 :)

SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
• Please give the docs team up to 1 week to review your PR unless you've added an urgent due date to it.
  Thanks in advance for your help!

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

EXTRA RESOURCES

• Sentry Docs contributor guide

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
sentry-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 11, 2024 6:00pm

[codecov]

Bundle Report

Changes will increase total bundle size by 14.74kB ⬆️

Bundle name	Size	Change
sentry-docs-server	7.57MB	14.75kB ⬆️
sentry-docs-client	6.21MB	6 bytes ⬇️
sentry-docs-edge-server	478.9kB	3 bytes ⬇️

[markushi]

Nice, lgtm!

[vivianyentran]

Thanks for updating this!