Themes: Load missing style attributes from original style

If a theme overrides a style in an app and does not include all
the attributes found in the original, it is possible for the app
to crash because it cannot locate an attribute it is expecting.

To overcome this we need to check the attributes in the original
style's bag and add any missing attributes to the current bag being
populated.  Currently we have only seen one theme that causes this
behavior, but there could be others out there or we may eventually
see this happen in the wild as apps update and the themes have not
had a chance to incorporate the new additions from the app.

Change-Id: Id44aa83a6c58a0b042d2b32171bed5e794352670
Themes: Avoid NPE when setting text in TickerView

It is possible, with the right timing, to receive an NPE in TextSwitcher
when a notification comes in during recreation of the status bar because
of a theme change.

Change-Id: Ia35ad0346f232df905ecff69158b71f3bf61a163
Themes: Fix setting wallpaper from a legacy theme

Change-Id: I3bfc9ee24d2a3ee5c1bdb97f2c07427e6d723206

Conflicts:
	services/java/com/android/server/ThemeService.java
Themes: Track NotFoundException on app launch failure

We should probably keep an eye on NotFoundExceptions too since they
are a common exception thrown when a bad theme is applied.

Change-Id: I2ccaed0349a90ab99b99fb83cef0c9183d598088