cts: Fixbuild

Change-Id: I2cdf6db05aa7282ce66576a66844ffd915599271
diff --git a/tests/tests/hardware/src/android/hardware/camera2/cts/helpers/Preconditions.java b/tests/tests/hardware/src/android/hardware/camera2/cts/helpers/Preconditions.java
index 38fd30c..0f7b0c8 100644
--- a/tests/tests/hardware/src/android/hardware/camera2/cts/helpers/Preconditions.java
+++ b/tests/tests/hardware/src/android/hardware/camera2/cts/helpers/Preconditions.java
@@ -16,6 +16,7 @@
 
 package android.hardware.camera2.cts.helpers;
 
+import java.util.Collection;
 import java.util.Objects;
 
 /**