[Android] Fix a crash when clickable view ids is sent as null in CCT

chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java

Index: chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
index b91fa20690f7bce6013d64caa3d3a20b07d4409a..abc157680d01caa7060be94929779ae259753cd1 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabIntentDataProvider.java
@@ -335,6 +335,7 @@ public class CustomTabIntentDataProvider {
      * @return A array of {@link View} ids, of which the onClick event is handled by the custom tab.
      */
     public int[] getClickableViewIDs() {
+        if (mClickableViewIds == null) return null;
         return mClickableViewIds.clone();
     }