title: Android Scan BLE Devices, problem after update Android Studio and/or upgrade targetSDK to 9.0
body: <p>I have an app already published, targetSDK 6, minSDK 5. This app use BLE API and I using this code</p>
  
  <pre><code>final BluetoothLeScanner bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
  
  List&lt;ScanFilter&gt; scanFilters = new ArrayList&lt;&gt;();
  
  ScanSettings.Builder builder = new ScanSettings.Builder();
  builder.setScanMode(ScanSettings.SCAN_MODE_OPPORTUNISTIC);
  
  if(Build.VERSION.SDK_INT &gt;= 23)
      builder.setCallbackType(ScanSettings.MATCH_MODE_AGGRESSIVE);
  
  if (Build.VERSION.SDK_INT &gt;= 26)
      builder.setLegacy(true);
  
  final ScanSettings settings = builder.build();
  
  bluetoothLeScanner.startScan(scanFilters, settings, mScanCallback);
  </code></pre>
  
  <p>now I upgraded Android Studio for Build Tool Versione 28.0.3</p>
  
  <ul>
  <li>Compile SDK Version API 28 (Pie 9)</li>
  <li>Target SDK Version API 28</li>
  <li>Min SDK API 23 (Marshmallow 6)</li>
  </ul>
  
  <p>My BLE Device uses bluetooth ble 4.1</p>
  
  <p>All compile...ok....but! I try to scan but it doesn't find anymore devices....
  no error, no exception....simply not find anything.</p>
  
  <p>can someone help me understand?
  help!</p>