audioflinger: Adjust priority of hal threads

HALs are prohibited from using framework binder, and there is
no equivalent scheduling policy service in hwbinder. Thus, in order
to match priorities of FastCapture / Mixer threads with their
counterparts in the HAL, it is needed to request the priority boost
from audioflinger on behalf of the HAL.

Test done to verify the priority was correctly set.

Bug: 34131400
Change-Id: If8b6b031c0fcba771fae901a5b8e7da89b3a1570
Test: check priority match between audioflinger's and hal's threads
diff --git a/media/utils/SchedulingPolicyService.cpp b/media/utils/SchedulingPolicyService.cpp
index 17ee9bc..d7055ef 100644
--- a/media/utils/SchedulingPolicyService.cpp
+++ b/media/utils/SchedulingPolicyService.cpp
@@ -28,7 +28,7 @@
 static const String16 _scheduling_policy("scheduling_policy");
 static Mutex sMutex;
 
-int requestPriority(pid_t pid, pid_t tid, int32_t prio, bool asynchronous)
+int requestPriority(pid_t pid, pid_t tid, int32_t prio, bool isForApp, bool asynchronous)
 {
     // FIXME merge duplicated code related to service lookup, caching, and error recovery
     int ret;
@@ -47,7 +47,7 @@
             sSchedulingPolicyService = sps;
             sMutex.unlock();
         }
-        ret = sps->requestPriority(pid, tid, prio, asynchronous);
+        ret = sps->requestPriority(pid, tid, prio, isForApp, asynchronous);
         if (ret != DEAD_OBJECT) {
             break;
         }