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

init/init_test.cpp

@@ -194,13 +194,10 @@ service A something
 }
 
 TEST(init, StartConsole) {
-    if (access("/dev/console", F_OK) < 0) {
-        GTEST_SKIP() << "/dev/console not found";
-    }
     std::string init_script = R"init(
 service console /system/bin/sh
     class core
-    console console
+    console null
     disabled
     user root
     group root shell log readproc