Bluetooth: Fix to avoid taking space as name upon orientation

Use case: Renaming the DUT name on orientation chnage

STR:
1) Go for the option of rename phone.
2) give only space characters.
3) The rename option shows disabled.
4) Change the orientation of the phone.
5) Check whether it accepts space as a name.

Failure: Renaming a phone with space characters gets
accepted during change in orientation.Accepted
space as BT name upon changing orientation

Root cause: There is no check for validating the input
string while renaming the device name on orientation change.

Fix: This fix is to avoid taking space character as a name in the
BluetoothNameDialogFragment upon orientation change from
PORTRAIT mode to LANDSCAPE mode and vice versa.

Change-Id: Ia66f27bb9b06739e42d73b15745c12a42512a1fc