Merge changes from topics "cherrypicker-L37800000954756398:N06400001268122372", "cherrypicker-L61200000954646707:N00900001267167505", "cherrypicker-L64000000954631044:N08200001267145803" into tm-dev
* changes:
Temporarily ignore ethernet tests until prebuilts are updated
Add CTS tests for EthernetNetworkProvider changes
Move EthernetNetworkFactory to using the NetworkProvider API
Add NetworkOfferCallback to NetworkInterfaceState
Change NetworkInterfaceState to hold NetworkProvider instance
Improve waiting for interface added or removed
Always wait for interface to be up in EthernetManagerTest
Assume all Ethernet interfaces have an MTU of 1500.