Use pid_t instead of not int32_t.

Bug: b/266595015
Test: atest PerformanceHintManagerTest
Change-Id: I33755bb30cceb9953db293092e417a1a14288226
diff --git a/include/android/performance_hint.h b/include/android/performance_hint.h
index 4a5bd5e..b494f89 100644
--- a/include/android/performance_hint.h
+++ b/include/android/performance_hint.h
@@ -37,6 +37,7 @@
 
 #include <android/api-level.h>
 #include <stdint.h>
+#include <unistd.h>
 
 __BEGIN_DECLS
 
@@ -173,7 +174,7 @@
  */
 int APerformanceHint_setThreads(
         APerformanceHintSession* session,
-        const int32_t* threadIds,
+        const pid_t* threadIds,
         size_t size) __INTRODUCED_IN(__ANDROID_API_U__);
 
 __END_DECLS