stagefright: define CB_CODEC_RELEASED and ReleaseReason enum.

        CB_OUTPUT_AVAILABLE = 2,

        CB_ERROR = 3,

        CB_OUTPUT_FORMAT_CHANGED = 4,

        CB_RESOURCE_RECLAIMED = 5,

        CB_CODEC_RELEASED = 5,

    };

    // used by CB_CODEC_RELEASED to tell the upper layer the cause of the release.

    enum ReleaseReason {

        REASON_UNKNOWN = 0,

        REASON_RECLAIMED,  // resources reclaimed by resource manager

    };

    struct BatteryNotifier;