Modify catch when addInterfaceToLocalNetwork() is called.

Modify catch when addInterfaceToLocalNetwork() is called.

Fatal Exception is occured in system process. Becuase addInterfaceToLocalNetwork()
throw IllegalStateException but it can not be handled in TetherInterfaceStateMachine.
Modify catch from "RemoteException" to "Exception" when addInterfaceToLocalNetwork() is called.

Test: Repeat on/off tethering
Test: "runtest --no-hidden-api-checks frameworks-net" passes

Bug: 110396460
Change-Id: I2f2f1325cfcce40c3113ccccf69b2bbd5df4ae5b
Signed-off-by: Sehee Park <sehee32.park@samsung.com>