Disabled Bluetooth if BLE is not supported

BluetoothManager is supported for Android API 18+. On older versions, skip
Bluetooth instead of crashing.

android-project/app/src/main/java/org/libsdl/app/HIDDeviceManager.java

@@ -7,6 +7,7 @@ import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.bluetooth.BluetoothManager;
 import android.bluetooth.BluetoothProfile;
+import android.os.Build;
 import android.util.Log;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -382,6 +383,11 @@ public class HIDDeviceManager {
             return;
         }
 
+        if (!mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE) || (Build.VERSION.SDK_INT < 18)) {
+            Log.d(TAG, "Couldn't initialize Bluetooth, this version of Android does not support Bluetooth LE");
+            return;
+        }
+
         // Find bonded bluetooth controllers and create SteamControllers for them
         mBluetoothManager = (BluetoothManager)mContext.getSystemService(Context.BLUETOOTH_SERVICE);
         if (mBluetoothManager == null) {