Revert "Adapt to libprocessgroup API changes for polling on cgro..."

This revert was created by Android Culprit Assistant. The culprit was identified in the following culprit search session (http://go/aca-get/91da3c52-9b76-498b-bdbd-a9de7d7ff53b).

Change-Id: Ib6098ab1fcfc29cd4f54d334816f31b7736254d5
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index 9b77b79..04525e8 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -1505,7 +1505,7 @@
      * fully removed, otherwise system resources may leak.
      * @hide
      */
-    public static final native boolean sendSignalToProcessGroup(int uid, int pid, int signal);
+    public static final native int sendSignalToProcessGroup(int uid, int pid, int signal);
 
     /**
       * Freeze the cgroup for the given UID.
diff --git a/core/jni/android_util_Process.cpp b/core/jni/android_util_Process.cpp
index edb95dd..18c60a7 100644
--- a/core/jni/android_util_Process.cpp
+++ b/core/jni/android_util_Process.cpp
@@ -1238,7 +1238,7 @@
     return killProcessGroup(uid, pid, SIGKILL);
 }
 
-jboolean android_os_Process_sendSignalToProcessGroup(JNIEnv* env, jobject clazz, jint uid, jint pid,
+jint android_os_Process_sendSignalToProcessGroup(JNIEnv* env, jobject clazz, jint uid, jint pid,
                                                  jint signal) {
     return sendSignalToProcessGroup(uid, pid, signal);
 }
@@ -1310,7 +1310,7 @@
         //{"setApplicationObject", "(Landroid/os/IBinder;)V",
         //(void*)android_os_Process_setApplicationObject},
         {"killProcessGroup", "(II)I", (void*)android_os_Process_killProcessGroup},
-        {"sendSignalToProcessGroup", "(III)Z", (void*)android_os_Process_sendSignalToProcessGroup},
+        {"sendSignalToProcessGroup", "(III)I", (void*)android_os_Process_sendSignalToProcessGroup},
         {"removeAllProcessGroups", "()V", (void*)android_os_Process_removeAllProcessGroups},
         {"nativePidFdOpen", "(II)I", (void*)android_os_Process_nativePidFdOpen},
         {"freezeCgroupUid", "(IZ)V", (void*)android_os_Process_freezeCgroupUID},