Scanning in background in Android should use a Pending Intent

**Describe the bug**
The current implementation does not allow connecting to BLE device after the app is backgrounrded

**To Reproduce**
Steps to reproduce the behavior:
1. Launch a BLE Scan
2. Close device screen
3. Broadcast on BLE device
4. Wait forever

**Expected behavior**
The app should find the device in the background

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Plugin version:**
- @capacitor-community/bluetooth-le: v6.0.1

**Additional context**
https://developer.android.com/develop/connectivity/bluetooth/ble/background

In android, to receive scan results in the background, the startScan method should be called with a Pending Intent and not a ScanResult

See https://github.com/android/platform-samples/blob/main/samples/connectivity/bluetooth/ble/src/main/java/com/example/platform/connectivity/bluetooth/ble/BLEScanIntentSample.kt#L114-L120 for an official example

Start at the Android BLE scanning implementation and its startScan entry point, then compare the current ScanResult-based call with the official BLEScanIntentSample.kt example linked in the issue. Done means BLE scan results can be received and the device is found after the app is backgrounded.

Written by the indexing model from the issue text.