Add safeguard against previous ethernet interfaces existing

The test EthernetManagerTest#testEnableDisableInterface_callbacks
captures the interface state changes of ethernet
interfaces that already exist instead of the test one created. Changes
the expectCallback to eventuallyExpect to account for this.

Test: atest EthernetManagerTest
Flag: TEST_ONLY
Bug: 333338569
Change-Id: Ic08444c87f93b3832c4fae1ce2f8382bbb71cb28
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index d052551..6fa2812 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -905,13 +905,17 @@
         val iface = createInterface()
         val listener = EthernetStateListener()
         addInterfaceStateListener(listener)
+        // Uses eventuallyExpect to account for interfaces that could already exist on device
+        listener.eventuallyExpect(iface, STATE_LINK_UP, ROLE_CLIENT)
+
+        disableInterface(iface).expectResult(iface.name)
+        listener.eventuallyExpect(iface, STATE_LINK_DOWN, ROLE_CLIENT)
+
+        enableInterface(iface).expectResult(iface.name)
         listener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
 
         disableInterface(iface).expectResult(iface.name)
         listener.expectCallback(iface, STATE_LINK_DOWN, ROLE_CLIENT)
-
-        enableInterface(iface).expectResult(iface.name)
-        listener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
     }
 
     @Test