fix(android): controls always show in fullscreen

[janpe]

Fixes #4734
Closes #4751

Summary

This is a rebase of the stale PR #4813 by @robertert (preserved as the first commit, original authorship intact), with the second commit addressing the review feedback from @moskalakamil:

• Drop the two inline explanatory comments
• Inline the shouldShowControls boolean in updateControllerVisibility
• Replace the explicit updateControllerConfig() + exoPlayerView.showController() on fullscreen entry with refreshControlsStyles(), which (after the first commit removes the !controls guard) refreshes visibility unconditionally

[janpe]

I'm open to closing this issue if @robertert's PR #4813 moves forward

There are failing checks but that seems like a pre-existing issue on the v6 branch

[janpe]

Heads up for reviewers: the red CI is unrelated to this change. The job fails at yarn install before the Android build runs, because mute-stream@4.0.0 was recently published with engines.node >= 22 and the workflow pins node-version: 20.x. Since there's no yarn.lock in the repo, fresh installs now resolve to the incompatible version.

Last green Build Android on support/6.x.x: run 26196236832 (2026-05-20). Anything merged into this branch after that point will hit the same failure until the workflow bumps Node (or a lockfile is added).

cc @moskalakamil — you approved #4813; this PR cherry-picks that commit (authorship preserved) and adds a second commit addressing your review nits.