fix(barcode-scanner): settle the pending scan() promise on cancel (fix #3560)

[ghostshreyash]

Fixes #3560.

Bug

On Android, cancel() tore the camera down but never settled the pending scan() promise. In BarcodeScannerPlugin.kt, cancel() called destroy() first, and destroy() sets savedInvoke = null, so the following savedInvoke?.reject("cancelled") was a no-op. Frontend code awaiting scan() was stranded forever, which is especially bad in windowed mode where the page background stays transparent.

Fix

Reject the pending invoke before calling destroy(). This is the order the iOS implementation already uses (self.invoke?.reject("cancelled") then destroy()), so both platforms now behave the same: scan() rejects with "cancelled", and cancel() itself resolves.

Verification

Built examples/api for Android (x86_64, debug) and ran it on an Android 16 / API 36 emulator, the same API level as in the report. Scanner view, Scan, then Cancel:

• Before (unpatched build) the console shows only cancelled, which is the example's own cancelScan() message. The scan() promise never settled, so its .catch never ran.
• After (this branch) the console shows { "message": "cancelled" } from scan().catch(...) followed by cancelled. The camera is released in both cases.

Changeset added for barcode-scanner and barcode-scanner-js (patch).

[github-actions]

Package Changes Through 4f483e4

There are 4 changes which include barcode-scanner with patch, barcode-scanner-js with patch, http with patch, http-js with patch

Planned Package Versions

The following package releases are the planned based on the context of changes in this pull request.

package	current	next
api-example	2.0.47	2.0.48
api-example-js	2.0.43	2.0.44
barcode-scanner	2.4.6	2.4.7
barcode-scanner-js	2.4.6	2.4.7
http	2.6.0	2.6.1
http-js	2.6.0	2.6.1

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