iterate over all SIMs/subscriptions and disable 2G

We need to disable 2G on all SIM cards, not just the first one.

This also checks if any of the subscriptions support cellular data to
decide if the feature is available or not.

Bug: 381265069
Test: enabled 2G, toggled APM, verified 2G is disabled in UI
Flag: android.security.aapm_feature_disable_cellular_2g
Change-Id: I4b650bdf6da904bdb59ebb4f3402140c3d1e7e43