test: use char arrays instead of strings

There is an issue in the assignment sequence for the vector filled in
with the static inline string in some compiler/linker combinations.
Therefore, use a byte array reference to build the string.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Idfb74f72b8cdbf9f30d0085379be0c5f29e18718
diff --git a/test/handler_unittest.cpp b/test/handler_unittest.cpp
index 789eefb..29420f6 100644
--- a/test/handler_unittest.cpp
+++ b/test/handler_unittest.cpp
@@ -33,11 +33,11 @@
 class BinaryStoreBlobHandlerBasicTest : public BinaryStoreBlobHandlerTest
 {
   protected:
-    static inline std::string basicTestBaseId = "/test/"s;
-    static inline std::string basicTestBlobId = "/test/blob0"s;
+    static inline char basicTestBaseId[] = "/test/";
+    static inline char basicTestBlobId[] = "/test/blob0";
 
     static const std::vector<std::string> basicTestBaseIdList;
-    static inline std::string basicTestInvalidBlobId = "/invalid/blob0"s;
+    static inline char basicTestInvalidBlobId[] = "/invalid/blob0";
 
     void addAllBaseIds()
     {