Skip testEcAttestation_DeviceLocked on emulator.

This CL is very similar to https://android-review.googlesource.com/c/platform/cts/+/1287934
It applies the skip to a similar test case (Ec instead of Rsa).

Bug: b/143143557, b/142324861
Test: run cts -m CtsKeystoreTestCases -t android.keystore.cts.KeyAttestationTest#testEcAttestation_DeviceLocked
Change-Id: Idaf772e4d501291a43f0b4041a0ea47512adaf10
(cherry picked from commit 7a3795d0aaad2e483716424043e326f130e24e56)
diff --git a/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java b/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
index f33d82c..4c330e0 100644
--- a/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
+++ b/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
@@ -228,6 +228,7 @@
     }
 
     @RestrictedBuildTest
+    @RequiresDevice
     public void testEcAttestation_DeviceLocked() throws Exception {
         String keystoreAlias = "test_key";
         Date now = new Date();