SoftApManager: no teardown when iface destroyed

When softap mode shuts down due to the iface being destroyed, no need to
explicitly call to teardown the iface.

Bug: 79441131
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: manually toggled wifi and tethering to verify client mode came up
Change-Id: I03a75b4569d4e86fd01a1ec0e144865a789a2bc9
2 files changed