Remoe usage of CollectionUtils as it's not exposed to mainline modules.

Bug: 140908357
Test: build
Change-Id: I5f56747be8bc4702e58b7fe27c21f7959bdd76de

1 files changed, 7 insertions, 0 deletions

diff --git a/telephony/common/com/android/internal/telephony/util/TelephonyUtils.java b/telephony/common/com/android/internal/telephony/util/TelephonyUtils.java
index a7ad884ca107..682697469af9 100644
--- a/telephony/common/com/android/internal/telephony/util/TelephonyUtils.java
+++ b/telephony/common/com/android/internal/telephony/util/TelephonyUtils.java
@@ -28,6 +28,8 @@ import android.os.RemoteException;
 import android.os.SystemProperties;
 
 import java.io.PrintWriter;
+import java.util.Collections;
+import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Supplier;
@@ -61,6 +63,11 @@ public final class TelephonyUtils {
         return str == null ? "" : str;
     }
 
+    /** Returns an empty list if the input is {@code null}. */
+    public static @NonNull <T> List<T> emptyIfNull(@Nullable List<T> cur) {
+        return cur == null ? Collections.emptyList() : cur;
+    }
+
     /** Throws a {@link RuntimeException} that wrapps the {@link RemoteException}. */
     public static RuntimeException rethrowAsRuntimeException(RemoteException remoteException) {
         throw new RuntimeException(remoteException);