storageproxyd: Start only a single binder thread

We only need a single binder thread to receive notifications, so we
should set the thread pool max to 0 rather than 1. startThreadPool()
starts one thread + the max count.

Test: m storageproxyd
Bug: 281951047
Fixes: 292030372
Change-Id: I53a90eaa2aa69469fd3a00b6da0d7061318c8ba9
1 file changed