Disable RatRatcheter feature for rats not in the same rat family

RatRatcheter feature will work between LTE and LTE CA rat even if
these are not set as families by KEY_RATCHET_RAT_FAMILIES because
NetworkRegistrationInfo#getAccessNetworkTechnology() always returns LTE
when data rat is LTE CA.

To fix this issue, check ServiceState#isUsingCarrierAggregation() to
determine if LTE/LTE CA rat has changed.

Test: manual - Checked that shall be displayed 4G icon when connect to
LTE from LTE_CA.
Test: auto - Passed RatRatcheterTest.
Bug: 153704793

Change-Id: I2ec69257839676f7f50e3fa77af8c565130329be