Run the console test with /dev/null

The availability of /dev/console varies across different devices and
even across different build variants (ex: userdebug/user). Instead of
relying on the device-specific condition, use the /dev/null as the
console device for the test.

Bug: 262090304
Test: atest CtsInitTestCases on raven-user
Change-Id: I3b12d66e94609328dfdd6f640d1adb88a773fa38