Revert "RESTRICT AUTOMERGE Prevent non-admin users from deleting system apps."

This reverts commit a7621e0ce0.

Reason for revert: Regression, DELETE_SYSTEM_APP flag no longer works

Change-Id: I7386d1ba3d61b95836b85c52214c83b216c478e8

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -18690,16 +18690,6 @@ public class PackageManagerService extends IPackageManager.Stub
                 return PackageManager.DELETE_FAILED_INTERNAL_ERROR;
             }
 
-            if (isSystemApp(uninstalledPs)) {
-                UserInfo userInfo = sUserManager.getUserInfo(userId);
-                if (userInfo == null || !userInfo.isAdmin()) {
-                    Slog.w(TAG, "Not removing package " + packageName
-                            + " as only admin user may downgrade system apps");
-                    EventLog.writeEvent(0x534e4554, "170646036", -1, packageName);
-                    return PackageManager.DELETE_FAILED_USER_RESTRICTED;
-                }
-            }
-
             disabledSystemPs = mSettings.getDisabledSystemPkgLPr(packageName);
             // Save the enabled state before we delete the package. When deleting a stub
             // application we always set the enabled state to 'disabled'.