Reduce metric error from assert to warn

If the controller does not support some command, we should not assert
but gracelly handle them.
This error is reported by an old version of Rootcanal that does not
handle oob and return an invalid command.

Bug: 333419772
Fix: 333419772
Test: atest CtsBluetoothTestCases:SystemBluetoothTest
Flag: Exempt, log change
Change-Id: I657ba5fc75ee94a2140ec31542140c2eedc37ce9