Add the new RIL requests and NetworkScanResult.

Those new RIL requests will be used to start and stop network scan, and
the scan result will be returned from RIL in the format of
NetworkScanResult.

Test: Telephony sanity tests
Bug: 30954762
Change-Id: I2bfd0fb8cbb3815cc62ec4385594dec9c5e4d279
(cherry picked from commit b36a4cb40222e1c0a61b13c1eca601ba761bd26e)
2 files changed