Adding in verification of calling UID in onShellCommand

Test: manual testing on device
Change-Id: I68903ebd6d3d85f4bc820b745e3233a448b62273
Bug: b/261709193

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

@@ -9488,6 +9488,10 @@ public class ActivityManagerService extends IActivityManager.Stub
     public void onShellCommand(FileDescriptor in, FileDescriptor out,
             FileDescriptor err, String[] args, ShellCallback callback,
             ResultReceiver resultReceiver) {
+        final int callingUid = Binder.getCallingUid();
+        if (callingUid != ROOT_UID && callingUid != Process.SHELL_UID) {
+            throw new SecurityException("Shell commands are only callable by root or shell");
+        }
         (new ActivityManagerShellCommand(this, false)).exec(
                 this, in, out, err, args, callback, resultReceiver);
     }