Tethering may use wrong sub id for entitlement when data
subscription is changed from preferred data sub id to CBRS
sub id. Fix by using the active data sub id for tethering.
Bug: 134994718
Test: -build, flash, boot
-FrameworkNetTests
-manual test with carrier SIMs
Change-Id: Icb3f5eeb2319e50b2dc98369ad152988c934da57