Provide better parsing of ABI in connection with API level for Droidium

Right now, there is not any tracking between available API levels and their respective ABI present in the system.

For example, when some AVD is not present in the system, Droidium tries to create it. While creating, it uses API level and when there exists ABI in configuration, it creates it with that ABI level.

For every API level present in the system, there should be information as which system images for that particular API level can be used while creating of AVD takes place.

Because of speed, default ABI will be choosen as x86 for some particular API level of users choice when he has not specified it explicitly. It is needed to filter available ABIs for some API level dynamically upon AVD creation.