Add Android.mk to build as part of roms.

Hi,

attached patch adds the ability to build the maps api as part of a rom. It pushes the permissions file and writes the jar to the correct location.

I did not add the addon.d files as it should not be used in this case:
- If you switch roms you'll most likely either use the prebuild mapsapi (which contains an addons.d) or gapps which would cause trouble with addons.d
- If you upgrade your ROM you should be getting a new version of the files anyway

The products list must be extended by com.google.android.maps and com.google.android.maps.xml