Revert "Add SkipPresubmit to EthernetManagerTest"

This reverts commit c2bc2963c19aeb5b25ffd09c5d4bec5166216db4.

Reason for revert: fixed flakiness. Re-enable EthernetManagerTest in presubmit.

Change-Id: I29f7d2b4f530b18aaaae3e327f3721f08aab060a
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index 1fc7922..d59b774 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -68,7 +68,6 @@
 import com.android.testutils.RecorderCallback.CallbackEntry.CapabilitiesChanged
 import com.android.testutils.RecorderCallback.CallbackEntry.Lost
 import com.android.testutils.RouterAdvertisementResponder
-import com.android.testutils.SkipPresubmit
 import com.android.testutils.TapPacketReader
 import com.android.testutils.TestableNetworkCallback
 import com.android.testutils.anyNetwork
@@ -119,7 +118,6 @@
 @RunWith(DevSdkIgnoreRunner::class)
 // This test depends on behavior introduced post-T as part of connectivity module updates
 @ConnectivityModuleTest
-@SkipPresubmit(reason = "Flaky: b/240323229; remove annotation after fixing")
 @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 class EthernetManagerTest {