Don't check canUseBiometric if caller is system process

Fixes: 128108006

Test: Secondary user is able to authenticate
Test: BiometricManager#canAuthenticate for secondary user works
Change-Id: Ia97f4a0972d92e4f6fbe1b634b318ba6e6fe93d3

services/core/java/com/android/server/biometrics/BiometricServiceBase.java

@@ -43,6 +43,7 @@ import android.os.IBinder;
 import android.os.IHwBinder;
 import android.os.IRemoteCallback;
 import android.os.PowerManager;
+import android.os.Process;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.SystemClock;
@@ -958,6 +959,10 @@ public abstract class BiometricServiceBase extends SystemService
             int pid, int userId) {
         checkUseBiometricPermission();
 
+
+        if (Binder.getCallingUid() == Process.SYSTEM_UID) {
+            return true; // System process (BiometricService, etc) is always allowed
+        }
         if (isKeyguard(opPackageName)) {
             return true; // Keyguard is always allowed
         }