Callback elision for HIDL interfaces.

HIDL interface types are now elided.

Bug: 31380743
Test: mma, hidl_test, hidl_test_java
Change-Id: Ie2bcd67b9f1d8dbd4331a3c29ae1294ba75d0be7
diff --git a/Interface.cpp b/Interface.cpp
index 7183ba8..df845d8 100644
--- a/Interface.cpp
+++ b/Interface.cpp
@@ -272,6 +272,10 @@
     return superType()->typeChain(); // should work even if superType is nullptr
 }
 
+bool Interface::isElidableType() const {
+    return true;
+}
+
 bool Interface::isInterface() const {
     return true;
 }