Add setting that controls network rate limit

The INGRESS_RATE_LIMIT_BYTES_PER_SECOND setting controls the rate limit
for internet networks. If set to -1, no rate limit applies.  There is
one global rate limit that will be applied to all networks with
NET_CAPABILITY_INTERNET.

Test: atest ConnectivitySettingsManagerTest
Bug: 157552970
Change-Id: Ia82aa867686d484ce46734f76d4a48bf864eff84
3 files changed