Switch to JPEGs for AOSPA Wallpapers

Some parts of Android expect images to be in JPEG format - Therefore this commit removes the PNGs & puts in the JPEG versions of the wallpaper.

Change-Id: Ic0b4731b5c6dab5212e881c821280372148011e7
Themes: Force recompiling common resources when scanning theme

If a theme is re-installed multiple times and in less time than
the 3 minute timout for common resources, it is possible for the
installation to fail because it does not compile the common resources.
This is not something an average user would encounter normally but
theme designers that are working on there theme and constantly
installing updates have a better chance of encountering this situation.
We simply remove the theme from mAvailableCommonResources which will
allow them to be recompiled.

Change-Id: I04b64645157dbb1d0c26fab95c851b34bfff3f42