This module includes two activities which are used to display
the list of all the installed APPs and detailed permissions
information of each APP. In the first activity, we override the
getAllApps() function of the class AppInfoProvider to access
the collection of the package structure of all APPs in the
system, and by iterating through all the package information
of the APPs and identifying the systematic APP or the
third-party APP through the FLAG_SYSTEM label to decide
whether to list the APP or not. Then, we use
requestedPermissions to get the permission information,
packageName to get the package name, loadIcon to get the
APP icon, loadLabel to obtain the name of the APP. To
present the permissions list, we rewrite the array adapter, and
define an AppBrowerAdapter class inherited BaseAdapter
class and override the method of getView() to set the data to
every specific small unit item of ListView.