fix: android attachment picker timing coordination

[isekovanic]

🎯 Goal

This PR stabilizes attachment picker and keyboard behavior on both Android and iOS by simplifying the picker open/close flow and removing timing based workarounds.

The main changes are:

• removed the delayed keyboard close/open coordination path
• removed forceClose() and the extra delayed close() fallback
• kept picker state changes aligned with bottom sheet state
• added a small handoff lock to prevent rapid picker/keyboard toggles from desynchronizing the composer and picker

Net result: picker/keyboard transitions are more reliable, the Android flicker/stuck states are resolved, and rapid toggling no longer leaves the composer and attachment picker out of sync.

This is now finally stable and correct on Android.

🛠 Implementation details

🎨 UI Changes

iOS

Before	After

Android

Before	After

🧪 Testing

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	351 KB	351 KB	-242 B	🚀