task_profiles_test: Skip this test if cgroups is read-only

GKE provides an unusual environment: the cgroupv2 filesystem is mounted
read-only. Skip the task_profiles_test on the host if the cgroup2
filesystem is mounted read-only to prevent that a test fails as
follows:

Failed to write '-1' to /sys/fs/cgroup/cgroup.procs: Read-only file system.

Bug: 278899193
Change-Id: I8c5a0c0848a47a395ae87f2fc31ba0ccda7d7f31
Signed-off-by: Bart Van Assche <bvanassche@google.com>