When setIncludeTestInterfaces(false) is called, any RTM_DELLINK
callback for a testtap interface is ignored, since the interface is no
longer considered to be a valid ethernet interface.
Change setIncludeTestInterfaces to go through all interfaces, and stop
tracking the ones which are no longer valid. Otherwise, they will
stick around forever (and break subsequent tests).
Bug: 390722214
Test: TH
Change-Id: Ied73e86c0452831f4d6b00f67908c51201af8bbd
d16138eeea