Add CtsConnectivityMultiDevicesTestCases for hotspot

This test is conducting two physical devices: a device
acting as the hotspot and a separate client device. The test
assesses whether the client can connect to the hotspot and utilize
its internet connection.

This test verifies the basic functionality of the hotspot feature
by exercising the entire system without mocking any component.
This is crucial because various system components, like cellular,
Wi-Fi, routing rules, tethering, and hardware offload, can have
regressions or design changes that impact the basic functionality.

Test: m connectivity_multi_devices_snippet && \
      atest CtsConnectivityMultiDevicesTestCases
      (2 physical devices near each other are needed
      to perform this test)
Bug: N/A
Change-Id: Ib97495c48f313889cedae03d59762482da10cfd8
7 files changed