Fix bug #15170508 When I initially load settings, all on/off toggles start in off position then move to on after pane loads

- refactor all the code that was using the Switch to control it thru the SwitchBar
- start the Switch as View.GONE and make it View.VISIBLE when it is set
as "enabled" or "checked" so that you dont see the Switch transition (it shows
only with it final state)

Change-Id: I382076bf3c819c530b5b2c06ca2429dfb2cdc6bf

src/com/android/settings/accessibility/ToggleScreenMagnificationPreferenceFragment.java

@@ -32,10 +32,10 @@ public class ToggleScreenMagnificationPreferenceFragment
     @Override
     protected void onInstallSwitchBarToggleSwitch() {
         super.onInstallSwitchBarToggleSwitch();
-        mToggleSwitch.setOnBeforeCheckedChangeListener(new OnBeforeCheckedChangeListener() {
+        mSwitchBar.setSwitchOnBeforeCheckedChangeListener(new OnBeforeCheckedChangeListener() {
                 @Override
             public boolean onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked) {
-                toggleSwitch.setCheckedInternal(checked);
+                mSwitchBar.setSwitchChecked(checked);
                 getArguments().putBoolean(AccessibilitySettings.EXTRA_CHECKED, checked);
                 onPreferenceToggled(mPreferenceKey, checked);
                 return false;