Fix "Rename device" BT settings to avoid accepting blank spaces.

Bug: 16157293
Change-Id: I0eddafd9fad89b76ab1d00005ca4a4f2725eb83e

src/com/android/settings/bluetooth/BluetoothNameDialogFragment.java

@@ -188,7 +188,7 @@ public final class BluetoothNameDialogFragment extends DialogFragment implements
         } else {
             mDeviceNameEdited = true;
             if (mOkButton != null) {
-                mOkButton.setEnabled(s.length() != 0);
+                mOkButton.setEnabled(s.toString().trim().length() != 0);
             }
         }
     }