Remove the old BluetoothLE starter App

It embeds an obsolete version of the BLE extension.

Change-Id: I63f6da2e537dac86ce7581cb11fbbdd74a5f68d4

appinventor/appengine/war/templates/BLuetoothLEStarter/BLuetoothLEStarter.json

-{"name":"BLuetoothLEStarter","subtitle":"MIT App Inventor BLuetoothLE starter project","description":" This template allow you to create a generic BluetoothLE enabled application.","link":"","thumbnail":"bluetooth.png","screenshot":"BluetoothLE_Starter.png"}