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/applications/ProcessStatsUi.java

@@ -25,7 +25,6 @@ import android.os.ServiceManager;
 import android.os.SystemClock;
 import android.os.UserManager;
 import android.preference.Preference;
-import android.preference.PreferenceActivity;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceGroup;
 import android.preference.PreferenceScreen;
@@ -40,6 +39,7 @@ import com.android.internal.app.IProcessStats;
 import com.android.internal.app.ProcessMap;
 import com.android.internal.app.ProcessStats;
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.fuelgauge.Utils;
 
 import java.io.IOException;
@@ -192,7 +192,7 @@ public class ProcessStatsUi extends PreferenceFragment
         args.putBoolean(ProcessStatsDetail.EXTRA_USE_USS, mUseUss);
         args.putLong(ProcessStatsDetail.EXTRA_MAX_WEIGHT, mMaxWeight);
         args.putLong(ProcessStatsDetail.EXTRA_TOTAL_TIME, mTotalTime);
-        ((PreferenceActivity) getActivity()).startPreferencePanel(
+        ((SettingsActivity) getActivity()).startPreferencePanel(
                 ProcessStatsDetail.class.getName(), args, R.string.details_title, null, null, 0);
 
         return super.onPreferenceTreeClick(preferenceScreen, preference);