Send hostname and MTU options in DHCP ACK/OFFER

The hostname option is only sent when requested in the requested
parameters option. This matches current behavior.

Test: with aosp/763982, regression tests now all pass
      atest FrameworksNetTest
Bug: b/109584964
Change-Id: I793173fa893750ddbe72be09f4c2d70e5b285837
4 files changed