Java class to represent the QosUpgrade enumerated type.
Documentation from the relevant specification:
The QoS-Upgrade AVP (AVP code 1030) is of type Enumerated. The value of the AVP indicates whether the SGSN supports that the GGSN upgrades the QoS in a Create PDP context response or Update PDP context response. If the SGSN does not support a QoS upgrade, the PCRF shall not provision an authorized bitrates (e.g. GBR, MBR) which are higher than the requested bitrates for this IP CAN bearer in the response of the IP-CAN session establishment or modification. The setting is applicable to the bearer indicated in the request within the Bearer-Identifier AVP. If no QoS-Upgrade AVP has been supplied for an IP CAN bearer, the default value QoS_UPGRADE_NOT_SUPPORTED is applicable. If the QoS-Upgrade AVP has previously been supplied for an IP CAN bearer but is not supplied in a new PCC rule request, the previously supplied value remains applicable.