Fix the inconsistency of scan status.

In types.hal and ril.h, the scan status is defined as:
    PARTIAL = 0x01
    COMPLETE = 0x02

But in NetworkScanResult.java, the scan status is defined as:
    public static final int SCAN_STATUS_PARTIAL = 0
    public static final int SCAN_STATUS_COMPLETE = 1

This CL makes changes to NetworkScanResult.java so that the scan status
is consistent both in Telephony and RIL.

Cherry-picked cleanly from:
https://android-review.googlesource.com/#/c/422183/

Test: Telephony sanity tests
Bug: 30954762

Merged-in: Iadcd344ad3fe682da98a1a41c2964583f67dc792
Change-Id: Iadcd344ad3fe682da98a1a41c2964583f67dc792
(cherry picked from commit ad50361e)