Revert "Revert "Don't force prepend I to header file names""

This reverts commit cc14a584a301533653639d9f6847111ca8a79c68.

Bug: 129549755
Test: m
Test: m libvirtualtouchpadclient
Test: ./runtests.sh
Merged-In: Id0103c1f05654c87a3eac449c985c805ae963d0e
Change-Id: Id0103c1f05654c87a3eac449c985c805ae963d0e
(cherry picked from commit 5b7e532899a56e88e5fbf53ffd6686d941be7da9)
diff --git a/aidl_to_cpp_common.cpp b/aidl_to_cpp_common.cpp
index 08ecf9b..9dbcadd 100644
--- a/aidl_to_cpp_common.cpp
+++ b/aidl_to_cpp_common.cpp
@@ -23,27 +23,27 @@
 namespace cpp {
 
 string ClassName(const AidlDefinedType& defined_type, ClassNames type) {
-  string c_name = defined_type.GetName();
-
-  if (c_name.length() >= 2 && c_name[0] == 'I' && isupper(c_name[1])) c_name = c_name.substr(1);
+  string base_name = defined_type.GetName();
+  if (base_name.length() >= 2 && base_name[0] == 'I' && isupper(base_name[1])) {
+    base_name = base_name.substr(1);
+  }
 
   switch (type) {
     case ClassNames::CLIENT:
-      c_name = "Bp" + c_name;
-      break;
+      return "Bp" + base_name;
     case ClassNames::SERVER:
-      c_name = "Bn" + c_name;
-      break;
+      return "Bn" + base_name;
     case ClassNames::INTERFACE:
-      c_name = "I" + c_name;
-      break;
+      return "I" + base_name;
     case ClassNames::DEFAULT_IMPL:
-      c_name = "I" + c_name + "Default";
-      break;
+      return "I" + base_name + "Default";
     case ClassNames::BASE:
-      break;
+      return base_name;
+    case ClassNames::RAW:
+      [[fallthrough]];
+    default:
+      return defined_type.GetName();
   }
-  return c_name;
 }
 
 std::string HeaderFile(const AidlDefinedType& defined_type, ClassNames class_type,