CtsNetTests: Fix WifiInfoTest

According to the public documentation of WifiInfo.getSSID(), the
returned value can be one of the following:
1. Hex digits if the SSID cannot be decoded as UTF-8.
2. String surrounded by double quotes if the SSID can be decoded as
UTF-8.
3. <unknown ssid>, if not connected.

Fix the test to check for all these 3 string values.

BUG: 31272462
TEST: The failing CTS test passes now.
Change-Id: I26e12d28994e3cdb4cd1bd9e999633b327ad5830
1 file changed