判断应用是否为系统应用

android.content.pm.PackageManager pm = ctx.getPackageManager();
List apps = pm.getInstalledApplications(0);
   
app.flags & ApplicationInfo.FLAG_SYSTEM == 1 //系统应用,反之是第三方
app.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP == 1 //通过升级,从系统应用变成第三方应用

boolean isSystem=(app.flags & ApplicationInfo.FLAG_SYSTEM )>0||(app.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP)>0