Use Drawer in Settings app

- get rid of PreferenceActivity as much as we can and use fragments instead
- add Drawer widget
- add Dashboard high level entry into the Drawer (but this is work in progress and would be done in another CL)
- add bypass of fragment's Header  validation when launched from the Drawer but *force* validation if external
call thru an Intent

Be aware that WifiPickerActivity should remain for now a PreferenceActivity. It is used by SetupWizard and should
not trigger running the SettingsActivity's header building code. SetupWizard is a Home during the provisionnig process
and then deactivate itself as a Home but would make the Home header to appear in the Drawer (because momentarily we
would have two Home).

Also, verified that:

- the WiFi settings still work when called from SetupWizard
- when you have multiple Launchers, the Home header will appear in the list of Headers in the Drawer

Change-Id: I407a5e0fdd843ad7615d3d511c416a44e3d97c90

src/com/android/settings/ChooseLockGeneric.java

@@ -17,7 +17,6 @@
 package com.android.settings;
 
 import android.app.Activity;
-import android.app.Fragment;
 import android.app.PendingIntent;
 import android.app.admin.DevicePolicyManager;
 import android.content.Context;
@@ -28,7 +27,6 @@ import android.os.Process;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
 import android.preference.PreferenceScreen;
 import android.security.KeyStore;
 import android.util.EventLog;
@@ -38,13 +36,12 @@ import android.view.ViewGroup;
 import android.widget.ListView;
 
 import com.android.internal.widget.LockPatternUtils;
-import com.android.settings.ConfirmLockPattern.ConfirmLockPatternFragment;
 
 import java.util.List;
 
 import libcore.util.MutableBoolean;
 
-public class ChooseLockGeneric extends PreferenceActivity {
+public class ChooseLockGeneric extends SettingsActivity {
 
     @Override
     public Intent getIntent() {