Add getThemedResourcesForApplicationAsUser()

Credit to @BigBrother1984 for the original cherry pick

Change-Id: I90b7cb441e4056f59b7260ffa55e31eba644e25a
Themes: Allow specifying a theme when creating a Context

A Context normally loads the resources associated with the given
package that this context is for.  This patch allows us to specify
a theme we want attached to a given context's resources.

Credit to @BigBrother1984 for the original cherry pick

Change-Id: Idfb53aba307f58be6e2ed6d404b8a76c31199fc8