Saving Bluetooth name to Max 248 character only.

Steps:
1. Set the BT name more than 248 character using SDK API set_name.
2. Check the BT Name on bt_config.
3. Name should be also visible Setting Apps on Bluetooth.

Failure: BluetoothAdapterProperties and stack are not in sync.
Root Cause: No check for the Bluetooth name length.
We can handle in framework layer but now handling in Stack.

Fix: Check the length of Bluetooth Name before writing to the file.

Test: Application and Stack BD Name are in sync
Bug: 35126970

Change-Id: I856a66e863cec68bee38762903a0b762ab0626d2