RIL: fix NeighboringCellInfo processing errors

Fix double subtraction of 116 from RSSI
Reject cells of network types other then GSM or UMTS

Signed-off-by: mvglasow <michael -at- vonglasow.com>
RIL: allow adding CellLocation or NeighboringCellInfo to CellTowerListLte

Signed-off-by: mvglasow <michael -at- vonglasow.com>
RIL: fix CellTower.isServing()

Signed-off-by: mvglasow <michael -at- vonglasow.com>
Remove unused import

Signed-off-by: mvglasow <michael -at- vonglasow.com>
RIL: Use all sources for LTE, update lists when network type changes

Signed-off-by: mvglasow <michael -at- vonglasow.com>