Do not tear down Bridged AP instance for -1 STA frequency.

WifiInfo.getFrequency() may return -1 after onL2Connected. We should
avoid checking this frequency against the SoftAP safe frequency list.

Bug: 230814082
Test: atest SoftApManagerTest
Change-Id: I4c9d16b73ea2c778b84c6a28d59c0a8de829947a
1 file changed