Include what you use: <cutils/bitops.h> for popcount

Test: builds OK
Change-Id: Ie717272df285303a63518f0342e1a4d2f41362c3
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index d51053b..133b3d0 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -42,6 +42,7 @@
 #include <set>
 #include <unordered_set>
 #include <vector>
+#include <cutils/bitops.h>
 #include <cutils/properties.h>
 #include <utils/Log.h>
 #include <media/AudioParameter.h>