message: fix parallel test issue

Both message/append and message/read were using the same
service name for testcases.  Ensure they use different service
names to allow parallel execution of test cases.

Change-Id: I060c03f69db0484b863af7cb45578f183cdff331
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/test/message/append.cpp b/test/message/append.cpp
index fcf3dd9..58d700f 100644
--- a/test/message/append.cpp
+++ b/test/message/append.cpp
@@ -9,7 +9,7 @@
 using verifyCallback_t = void(*)(sd_bus_message*);
 verifyCallback_t verifyCallback = nullptr;
 
-static constexpr auto SERVICE = "sdbusplus.test";
+static constexpr auto SERVICE = "sdbusplus.test.message.append";
 static constexpr auto INTERFACE = SERVICE;
 static constexpr auto TEST_METHOD = "test";
 static constexpr auto QUIT_METHOD = "quit";