Change RouteController from free functions/members to class functions.

In a future change, this will make it more explicit which bits of
state (e.g., locks) are part of the class and which are not.

Test: netd_{unit,integration}_test passes
Change-Id: Iff5a202cdcb26a7b6039dd95655cc2c26592fc36
diff --git a/server/RouteControllerTest.cpp b/server/RouteControllerTest.cpp
index 090b383..62540b9 100644
--- a/server/RouteControllerTest.cpp
+++ b/server/RouteControllerTest.cpp
@@ -30,6 +30,10 @@
     RouteControllerTest() {
         RouteController::iptablesRestoreCommandFunction = fakeExecIptablesRestoreCommand;
     }
+
+    int flushRoutes(uint32_t a) {
+        return RouteController::flushRoutes(a);
+    }
 };
 
 TEST_F(RouteControllerTest, TestGetRulePriority) {