Implement direct boot awareness

To do direct boot, important files need to be moved to device storage (i.e. not as safe storage). The only thing sensitive is user credentials (server settings in each profile) and the config file passed to libss-*.so. In order to implement direct boot, at least the active profile has to be moved/copied to device storage.

This commit keeps profile information (and temporary data used by ProfileConfigFragment) and Shadowsocks config in credential storage and move everything else to device storage. In order to make direct boot work, active profile is also copied into device storage and Shadowsocks config file is created in device storage during direct boot. Cleanup of those information is also implemented.

Fixes #1457.

NB:

* `android:directBootAware` can't be used on application element. That seems to be used by system apps.
* Works fine with multi-user;
* Old GSM files are not migrated (see App.kt) to device storage.

mobile/src/main/java/com/github/shadowsocks/ProfileConfigFragment.kt

@@ -45,6 +45,7 @@ import com.github.shadowsocks.preference.IconListPreference
 import com.github.shadowsocks.preference.OnPreferenceDataStoreChangeListener
 import com.github.shadowsocks.preference.PluginConfigurationDialogFragment
 import com.github.shadowsocks.utils.Action
+import com.github.shadowsocks.utils.DirectBoot
 import com.github.shadowsocks.utils.Key
 import com.takisoft.fix.support.v7.preference.EditTextPreference
 import com.takisoft.fix.support.v7.preference.PreferenceFragmentCompatDividers
@@ -62,7 +63,7 @@ class ProfileConfigFragment : PreferenceFragmentCompatDividers(), Toolbar.OnMenu
     private lateinit var pluginConfiguration: PluginConfiguration
 
     override fun onCreatePreferencesFix(savedInstanceState: Bundle?, rootKey: String?) {
-        preferenceManager.preferenceDataStore = DataStore
+        preferenceManager.preferenceDataStore = DataStore.privateStore
         val activity = activity!!
         val profile = ProfileManager.getProfile(activity.intent.getIntExtra(Action.EXTRA_PROFILE_ID, -1))
         if (profile == null) {
@@ -102,7 +103,7 @@ class ProfileConfigFragment : PreferenceFragmentCompatDividers(), Toolbar.OnMenu
         pluginConfigure.onPreferenceChangeListener = this
         initPlugins()
         app.listenForPackageChanges { initPlugins() }
-        DataStore.registerChangeListener(this)
+        DataStore.privateStore.registerChangeListener(this)
     }
 
     private fun initPlugins() {
@@ -130,6 +131,7 @@ class ProfileConfigFragment : PreferenceFragmentCompatDividers(), Toolbar.OnMenu
         profile.deserialize()
         ProfileManager.updateProfile(profile)
         ProfilesFragment.instance?.profilesAdapter?.deepRefreshId(profile.id)
+        if (DataStore.profileId == profile.id && DataStore.directBootAware) DirectBoot.update()
         activity!!.finish()
     }
 
@@ -201,7 +203,7 @@ class ProfileConfigFragment : PreferenceFragmentCompatDividers(), Toolbar.OnMenu
     }
 
     override fun onDestroy() {
-        DataStore.unregisterChangeListener(this)
+        DataStore.privateStore.unregisterChangeListener(this)
         super.onDestroy()
     }
 }