support all capital method name in c++

if there is a method with all capital name, it conflicts with the enum's name for the transaction ID

so remove enum and write hardcorded transaction id to prevent misuse
from client

Bug: 119525871
Test: ./runtests.sh
Test: m -j
Change-Id: Ia82b16b6262256449f4da29b549bdd74812aec5d
diff --git a/aidl_to_cpp.cpp b/aidl_to_cpp.cpp
index 17fa3d8..efd5b6b 100644
--- a/aidl_to_cpp.cpp
+++ b/aidl_to_cpp.cpp
@@ -21,6 +21,8 @@
 #include <functional>
 #include <unordered_map>
 
+using std::ostringstream;
+
 namespace android {
 namespace aidl {
 namespace cpp {
@@ -138,6 +140,15 @@
   c.writer << "\n";
 }
 
+std::string GetTransactionIdFor(const AidlMethod& method) {
+  ostringstream output;
+
+  if (method.IsUserDefined()) {
+    output << "::android::IBinder::FIRST_CALL_TRANSACTION + ";
+  }
+  output << method.GetId() << " /* " << method.GetName() << " */";
+  return output.str();
+}
 }  // namespace cpp
 }  // namespace aidl
 }  // namespace android