feat(feedback): Add per-form shake detection and sample app showcases (#5353)

* feat(feedback): Add per-form shake detection and sample app showcases

Resolve feedback options once in the constructor and reuse them in
onCreate, avoiding duplicate resolution. Add per-form shake-to-show
support via SentryShakeDetector that skips activation when the global
FeedbackShakeIntegration is already enabled. Update sample app with
custom form builder, auto-dismiss, programmatic capture, and
shake-to-show examples.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs(changelog): Add per-form shake detection entry

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Format code

* docs(changelog): Add usage example for per-form shake detection

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs(changelog): Use Kotlin example and clarify per-screen usage

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* ref(feedback): Extract shared shake listener in SentryUserFeedbackForm

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Sentry Github Bot <bot+github-bot@sentry.io>