Enforce variable init

There were a few places we weren't initting our variables per cpp core
guidelines.  Fix all of them, and enable checks for this.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Iba09924beb9fb26f597ff94d1cecbd6d6b1af912
diff --git a/include/sessions.hpp b/include/sessions.hpp
index 79e71ce..b445915 100644
--- a/include/sessions.hpp
+++ b/include/sessions.hpp
@@ -46,7 +46,7 @@
     std::string clientId;
     std::string clientIp;
     std::chrono::time_point<std::chrono::steady_clock> lastUpdated;
-    PersistenceType persistence;
+    PersistenceType persistence{PersistenceType::TIMEOUT};
     bool cookieAuth = false;
     bool isConfigureSelfOnly = false;