fix: correct Android video codec library names

[Foesa-yyx]

Summary

• correct Android video decoder and encoder library names in the English app-size and download pages
• separate the merged Video Encoding and Video Decoding tables so Markdown alignment markers are not rendered as data rows
• restore the missing Video Decoding section across all repeated SDK/platform content
• keep the verified Windows DLL and Apple xcframework names unchanged

Verification

• inspected the official 4.2.0 and 4.6.2 Android codec AAR contents across all four ABIs
• verified no unprefixed Android codec library references remain
• verified the RTC accordion and Broadcast Streaming table variants in a local browser
• confirmed both codec tables render with one header and 10 data rows, with no alignment-marker row
• bun run types:check
• git diff --check

[github-actions]

Vercel Preview

Preview URL: https://docs-portal-lvjc8nw1x-agora-gdxe.vercel.app