Clean up inotify tests.
Clean up inotify tests.

Mostly simplifies SKIP_IF statements and adds some more documentation.
Also, mknod is now supported by gofer fs, so remove SKIP_IFs related to this.

PiperOrigin-RevId: 333449932

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor