ANDROID: Export cpu_busy_with_softirqs()

This function used to be called task_may_not_preempt() in older versions
and used by modules that have their extension to RT. Export it to allow
users to continue to use it.

Bug: 332629555
Signed-off-by: Qais Yousef <qyousef@google.com>
Change-Id: I04affb8e9e6258f9fb36ebab4d7956a265e9e299