Add libprocessgroup dependency and fix sched_policy include

libaudioclient and libmedia are using get_sched_policy and
set_sched_policy which are now implemented inside libprocessgroup.
Add required dependencies and include required headers.

Exempt-From-Owner-Approval: janitorial

Bug: 111307099
Test: builds, boots

Change-Id: I83dd6878839122e3ea71b7be6f6f312376897d56
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/media/libaudioclient/AudioTrack.cpp b/media/libaudioclient/AudioTrack.cpp
index b444d2d..e9a0e22 100644
--- a/media/libaudioclient/AudioTrack.cpp
+++ b/media/libaudioclient/AudioTrack.cpp
@@ -29,6 +29,7 @@
 #include <media/AudioTrack.h>
 #include <utils/Log.h>
 #include <private/media/AudioTrackShared.h>
+#include <processgroup/sched_policy.h>
 #include <media/IAudioFlinger.h>
 #include <media/IAudioPolicyService.h>
 #include <media/AudioParameter.h>