Add missing isShellUser check

Bug: 160390416
Test: verified command still works from shell
Change-Id: I23bb06e00f1623e4f27c02d7eb2c0d273b40771b
Merged-In: I23bb06e00f1623e4f27c02d7eb2c0d273b40771b
(cherry picked from commit 80a9cce44b52081033b730729c6ce0a1bb9edf87)

Author: jreck

services/core/java/com/android/server/am/ActivityManagerService.java

@@ -3174,6 +3174,10 @@ public int getPackageProcessState(String packageName, String callingPackage) {
     @Override
     public boolean setProcessMemoryTrimLevel(String process, int userId, int level)
             throws RemoteException {
+        if (!isCallerShell()) {
+            EventLog.writeEvent(0x534e4554, 160390416, Binder.getCallingUid(), "");
+            throw new SecurityException("Only shell can call it");
+        }
         synchronized (this) {
             final ProcessRecord app = findProcessLocked(process, userId, "setProcessMemoryTrimLevel");
             if (app == null) {