ethernet: use short timeout for assumeNoInterfaceForTetheringAvailable

assumeNoInterfaceForTetheringAvailable checks if an interface is
available for tethering and throws and assumption failure accordingly.
If a physical interface is present, onAvailable() will be called almost
immediately, so there is no need to ever wait for TIMEOUT_MS. This is
especially important now that TIMEOUT_MS is being increased to 10s.

Test: atest EthernetManagerTest
Change-Id: I2f58d7690dbe4c25cfb01a8b29717cea6a01ab32
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index 122eb15..e56602c 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -303,8 +303,8 @@
             available.completeExceptionally(IllegalStateException("onUnavailable was called"))
         }
 
-        fun expectOnAvailable(): String {
-            return available.get(TIMEOUT_MS, TimeUnit.MILLISECONDS)
+        fun expectOnAvailable(timeout: Long = TIMEOUT_MS): String {
+            return available.get(timeout, TimeUnit.MILLISECONDS)
         }
 
         fun expectOnUnavailable() {
@@ -623,7 +623,7 @@
         // see aosp/2123900.
         try {
             // assumeException does not exist.
-            requestTetheredInterface().expectOnAvailable()
+            requestTetheredInterface().expectOnAvailable(NO_CALLBACK_TIMEOUT_MS)
             // interface used for tethering is available, throw an assumption error.
             assumeTrue(false)
         } catch (e: TimeoutException) {