hidl-gen: remove references to AIDL

git grep -l _aidl_ . | xargs sed -i -e 's/_aidl_/_hidl_/g'

b/30778629 Generated code has many references to AIDL

Change-Id: I3172e7da7acd6ba8c8c332be7316317b0eb59136
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/Interface.cpp b/Interface.cpp
index 158f874..a9b27af 100644
--- a/Interface.cpp
+++ b/Interface.cpp
@@ -50,12 +50,12 @@
         parcelObj + (parcelObjIsPointer ? "->" : ".");
 
     if (isReader) {
-        const std::string binderName = "_aidl_" + name + "_binder";
+        const std::string binderName = "_hidl_" + name + "_binder";
 
         out << "::android::sp<::android::hardware::IBinder> "
             << binderName << ";\n";
 
-        out << "_aidl_err = ";
+        out << "_hidl_err = ";
         out << parcelObjDeref
             << "readNullableStrongBinder(&"
             << binderName
@@ -70,7 +70,7 @@
             << binderName
             << ");\n";
     } else {
-        out << "_aidl_err = ";
+        out << "_hidl_err = ";
         out << parcelObjDeref
             << "writeStrongBinder("
             << fullName()