isBinder -> isInterface.

There are two functions here which do the same thing. To make handling
interfaces in various cases clearer/easier to understand, these are
being combined.

Bug: 111320612
Test: hidl_test
Change-Id: I3ebf0ec644f73d25657632564c29243952fdd0d4
diff --git a/VectorType.cpp b/VectorType.cpp
index cb7a658..f883da7 100644
--- a/VectorType.cpp
+++ b/VectorType.cpp
@@ -75,7 +75,7 @@
 }
 
 bool VectorType::isVectorOfBinders() const {
-    return mElementType->isBinder();
+    return mElementType->isInterface();
 }
 
 bool VectorType::deepCanCheckEquality(std::unordered_set<const Type*>* visited) const {