PR: Update BluetoothLeGatt Project to use BluetoothLeScanner

[falconsmilie]

Hi.

I created this PR a few days ago.

I would like to create a new PR which would include the PR from above. This new PR will remove the deprecated calls to LE methods in the BluetoothAdapter, and replace them with calls to BluetoothLeScanner.

There is a commit here, which includes the changes.

Kind regards,
Shane