ANDROID: binder: Add vendor hook to fix priority restore

When cpu loading is high, the task maybe preempted after restoring the
sched priority in trace_android_vh_binder_free_buf(). This means that
node->has_async_transaction can't be cleared immediately and the work
isn't added to the proc->todo queue as soon as possible.

To fix this we add a new hook trace_android_vh_binder_free_buf() to
restore the priority after node->has_async_transaction has been updated
and the node->work has been added to the proc->todo queue.

Note: the old trace_android_vh_binder_free_buf() hook is kept to avoid
breaking KMI but is not extrictly needed.

Bug: 325855598
Fixes: 0eb66ec3 ("ANDROID: vendor_hooks: Add hooks for binder")
Change-Id: I8126c79c9c68faa3ce0cd87ce83e2591bd61d5dd
Signed-off-by: Fuchun Liao <lfc@oppo.com>
[cmllamas: fix-up commit log and variable naming]
Signed-off-by: Carlos Llamas <cmllamas@google.com>