Fix systemui crash on boot

The process com.android.systemui would crash after phone booting with a
java.lang.NullPointerException when the signal status style is set to text

Change-Id: Ia7b58fa93b8591d0571b90a57a2fe0fe823b3f45
Fix ResourceNotFoundException when updating  applied theme

If the user has a theme applied and there is an update to that theme,
then the themed apps will crash. This is because the theme's APK path changes,
but the apps do not update their resources. Apps were not updating their resources
because updateConfiguration() determined that the config (which only has pkgName) hasn't changed.

The problem is fixed by first applying the default theme config and then re-applying the
updated theme.

SystemUI was crashing with a NPE while verifying this fix, so a NP check was added to SystemUI as well.

Change-Id: I00e32fc1535b4d279fcb37c35f868501ecc1dd19
IconPackHelper: Respect the original size of bitmap icons

When use icon packs on low-resolution devices, for example, my HDPI
phone, it seems that using the size returned by
getLauncherLargeIconSize() will cause a blurness on
some icons that are not included in the icon pack because of the compose
function.

This patch respects the original size of the icon if the icon is an
instance of BitmapDrawable but use the size returned by
getLauncherLargeIconSize() if the icon is an instance of PaintDrawable.
This will remove icon blurness on low-resolution devices.

Change-Id: Ifcb39020d934a9c7cb409e1206a179d64f99aa37