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/location/RecentLocationApps.java

@@ -26,10 +26,10 @@ import android.os.Bundle;
 import android.os.Process;
 import android.os.UserHandle;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
 import android.util.Log;
 
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.applications.InstalledAppDetails;
 
 import java.util.ArrayList;
@@ -44,10 +44,10 @@ public class RecentLocationApps {
 
     private static final int RECENT_TIME_INTERVAL_MILLIS = 15 * 60 * 1000;
 
-    private final PreferenceActivity mActivity;
+    private final SettingsActivity mActivity;
     private final PackageManager mPackageManager;
 
-    public RecentLocationApps(PreferenceActivity activity) {
+    public RecentLocationApps(SettingsActivity activity) {
         mActivity = activity;
         mPackageManager = activity.getPackageManager();
     }