Remove binder threadpool init from puller tests

LibStatsPullTests used to manually create a binder threadpool. However,
it seems that it is automatically done for us now, so we should not
override the defaults since this can result in shrinking the threadpool:
b/150904425.

Test: atest LibStatsPullTests
Bug: 150904425
Change-Id: I3f1a95aba3681c43fd46a9448c93a71fcb3133a9

apex/statsd/tests/libstatspull/jni/stats_pull_helper.cpp

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-#include <android/binder_process.h>
 #include <jni.h>
 #include <log/log.h>
 #include <stats_event.h>
@@ -32,17 +31,6 @@ static int64_t sLatencyMillis;
 static int32_t sAtomsPerPull;
 static int32_t sNumPulls = 0;
 
-static bool initialized = false;
-
-static void init() {
-    if (!initialized) {
-        initialized = true;
-        // Set up the binder
-        ABinderProcess_setThreadPoolMaxThreadCount(9);
-        ABinderProcess_startThreadPool();
-    }
-}
-
 static AStatsManager_PullAtomCallbackReturn pullAtomCallback(int32_t atomTag, AStatsEventList* data,
                                                              void* /*cookie*/) {
     sNumPulls++;
@@ -62,7 +50,6 @@ Java_com_android_internal_os_statsd_libstats_LibStatsPullTests_registerStatsPull
         JNIEnv* /*env*/, jobject /* this */, jint atomTag, jlong timeoutNs, jlong coolDownNs,
         jint pullRetVal, jlong latencyMillis, int atomsPerPull)
 {
-    init();
     sAtomTag = atomTag;
     sPullReturnVal = pullRetVal;
     sLatencyMillis = latencyMillis;