netd: Enable clang-tidy and fix all warnings

Bug: 65246407
Test: m netd && system/netd/tests/runtests.sh
Change-Id: I1d22b2bc317fe7218ccde78859ed0623d6a1f8df
diff --git a/server/IptablesRestoreControllerTest.cpp b/server/IptablesRestoreControllerTest.cpp
index 45b05f0..7ccb1ce 100644
--- a/server/IptablesRestoreControllerTest.cpp
+++ b/server/IptablesRestoreControllerTest.cpp
@@ -81,7 +81,7 @@
     // We can't readlink /proc/PID/exe, because zombie processes don't have it.
     // Parse /proc/PID/stat instead.
     std::string statPath = StringPrintf("/proc/%d/stat", pid);
-    int fd = open(statPath.c_str(), O_RDONLY);
+    int fd = open(statPath.c_str(), O_RDONLY | O_CLOEXEC);
     if (fd == -1) {
       // ENOENT means the process is gone (expected).
       ASSERT_EQ(errno, ENOENT)
@@ -131,7 +131,7 @@
   }
 
   int acquireIptablesLock() {
-    mIptablesLock = open(XT_LOCK_NAME, O_CREAT, 0600);
+    mIptablesLock = open(XT_LOCK_NAME, O_CREAT | O_CLOEXEC, 0600);
     if (mIptablesLock == -1) return mIptablesLock;
     int attempts;
     for (attempts = 0; attempts < XT_LOCK_ATTEMPTS; attempts++) {