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
diff --git a/trusty/storage/proxy/proxy.c b/trusty/storage/proxy/proxy.c
index 3b744ec..67e935e 100644
--- a/trusty/storage/proxy/proxy.c
+++ b/trusty/storage/proxy/proxy.c
@@ -243,9 +243,12 @@
      * Start binder threadpool. At least one extra binder thread is needed to
      * connect to the wakelock service without relying on polling. If we poll on
      * the main thread we end up pausing for at least 1s even if the service
-     * starts faster.
+     * starts faster. We set the max thread count to 0 because startThreadPool
+     * "Starts one thread, PLUS those requested in setThreadPoolMaxThreadCount,
+     * PLUS those manually requested in joinThreadPool." We only need a single
+     * binder thread to receive notifications on.
      */
-    ABinderProcess_setThreadPoolMaxThreadCount(1);
+    ABinderProcess_setThreadPoolMaxThreadCount(0);
     ABinderProcess_startThreadPool();
 
     /* initialize secure storage directory */