Sync state machine between Service and Activity

[Yuan-Chen Cheng]

Currently state machine flag is not sync between Service and Activity.

For Service:

    public enum ServiceState {
        READY, FETCHING_CHANNELS, DOWNLOADING, INSTALLING, UNINSTALLING_UBUNTU, DELETING_USER_DATA
    }

For Activity:

    private enum ActivityStatus {
        NORMAL, FETCHING_CHANNELS, NO_CHANNELS, READY_TO_DOWNLOAD, DOWNLOADING, READY_TO_INSTALL, INSTALLING
    };

A Unified design should be done !

[Ethan Chang (ethan.chang)]

Verified in build M4-beta2