DO NOT MERGE Block the user from entering safe boot mode

Block the user from entering safe boot mode if the DISALLOW_SAFE_BOOT
policy is set.

Bug: 26251884
Change-Id: I4945d5d676928346c11ea305a5b6a2e1a42e94e6

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -65,6 +65,7 @@ import android.os.SystemProperties;
 import android.os.SystemService;
 import android.os.Trace;
 import android.os.UserHandle;
+import android.os.UserManager;
 import android.os.WorkSource;
 import android.provider.Settings;
 import android.util.ArraySet;
@@ -7612,6 +7613,12 @@ public class WindowManagerService extends IWindowManager.Stub
                    + " milliseconds before attempting to detect safe mode.");
         }
 
+        UserManager um = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
+        if (um != null && um.hasUserRestriction(UserManager.DISALLOW_SAFE_BOOT)) {
+            mSafeMode = false;
+            return false;
+        }
+
         int menuState = mInputManager.getKeyCodeState(-1, InputDevice.SOURCE_ANY,
                 KeyEvent.KEYCODE_MENU);
         int sState = mInputManager.getKeyCodeState(-1, InputDevice.SOURCE_ANY, KeyEvent.KEYCODE_S);