[hidl2aidl] Convert the newest interfaces

This goes through the directory structure to find all the minor
versions. Then it compiles the latest minor version of each interface.

If a specific interface is provided then it fails to compile if a newer
version of that interface is present.

Bug: 137551286
Test: m hidl2aidl_test
Test: hidl2aidl -rhidl2aidl:system/tools/hidl/hidl2aidl/test -o tmp
hidl2aidl@1.0::IFoo should error
Change-Id: I5d10ec4f6ce1a8b82e4dbbfc6f2a6e5ebe4aad35
diff --git a/Coordinator.h b/Coordinator.h
index c62a92c..7715e56 100644
--- a/Coordinator.h
+++ b/Coordinator.h
@@ -114,6 +114,9 @@
             const FQName &package,
             std::vector<std::string> *fileNames) const;
 
+    // Returns true if the package points to a directory that exists
+    status_t packageExists(const FQName& package, bool* result) const;
+
     status_t appendPackageInterfacesToVector(
             const FQName &package,
             std::vector<FQName> *packageInterfaces) const;