make android scanner mode configurable

[Raz1e1]

This introduces a new option the the ScanDocumentOptions to allow the configuration of the used scanner mode on android.

https://developers.google.com/ml-kit/vision/doc-scanner#customization

The supported modes are

SCANNER_MODE_BASE: basic editing capabilities (crop, rotate, reorder pages, etc…).
SCANNER_MODE_BASE_WITH_FILTER: adds image filters (grayscale, auto image enhancement, etc…) to the SCANNER_MODE_BASE mode.
SCANNER_MODE_FULL (default): adds ML-enabled image cleaning capabilities (erase stains, fingers, etc…) to the 

The option can be set like this

    const {scannedImages, status} = await DocumentScanner.scanDocument({
      maxNumDocuments: 50,
      androidScannerMode: AndroidScannerMode.ScannerModeBase
    });

Also upgraded the gradle build tools.