Use Widely Supported GSM Channels for NetworkScan

Change the network scan tests to use the P900 and 850
GSM bands, which are commonly (nearly universally) supported
bands.

Bug: 132076611
Test: atest RadioHidlTest_v1_2
Merged-In: Ia682f022d35c481876c49c9c8802d7c39722be0e
Change-Id: Ia682f022d35c481876c49c9c8802d7c39722be0e
(cherry picked from commit 2ea2a64b)