[SM05] Enable record mobile network stats by collapsed rat type

Switch on the recording in device side. Metrics will be
collected in follow-up patches which can be independently
enabled/disabled.

This change also fix the fail in NetworkStatsCollectionTest
which caused by enabling this feature, where the rounding
problem happened when records are distributed into smaller
buckets and categorized into more NetworkIdentity.

Test: atest FrameworksNetTests
Bug: 129082217
Change-Id: If330e85330a4ff713dd420c98d42fa741eabd90a