Let lock_guard deduce its template argument

No functional change, this is a cleanup.

With C++17, it's no longer necessary to specify the teplate argument
when it can be deduced from the types of constructor arguments. This
allows de-cluttering our locking statements.

To avoid typos, this patch was mechanically generated:

  perl -p -i -e 's/std::lock_guard<std::mutex>/std::lock_guard/g' \
    $(find . -name '*.cpp' -o -name '*.h')

Change-Id: Ibb15d9a6c5b1c861d81353e47d25474eb1d4c2df
diff --git a/server/EventReporter.cpp b/server/EventReporter.cpp
index c9238f4..52aaf16 100644
--- a/server/EventReporter.cpp
+++ b/server/EventReporter.cpp
@@ -37,7 +37,7 @@
 }
 
 android::sp<INetdEventListener> EventReporter::getNetdEventListener() {
-    std::lock_guard<std::mutex> lock(mutex);
+    std::lock_guard lock(mutex);
     if (mNetdEventListener == nullptr) {
         // Use checkService instead of getService because getService waits for 5 seconds for the
         // service to become available. The DNS resolver inside netd is started much earlier in the