Add condition to check case of accessory combinations

Before this CL, we only compare whether the value of function is
equal to accessory to ensure usb is in accessory mode. But in some
cases there are different accessory combinations, like
"accessory,audio source". It will make the condition return false
when encountering accessory combinations.

This CL will check whether the function will include accessory mode
to fix this issue.

Bug: 162451162
Test: make -j42 RunSettingsRoboTests
Change-Id: I7c80f02de5340799e292949608e19b86b187b982