UMA: include missing headers in cellular_logic_helper

No change to logic.

This adds two header files which this C++ file was depending on
transitively (for base::TimeDelta and OS_ANDROID/OS_IOS).

Bug: 1010369
Test: N/A
Change-Id: I16ceb2d05beaca66ea254f1e1c7ddd541b8ff05c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1835132Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702155}

components/metrics/net/cellular_logic_helper.cc

@@ -4,6 +4,8 @@
 
 #include "components/metrics/net/cellular_logic_helper.h"
 
+#include "base/time/time.h"
+#include "build/build_config.h"
 #include "net/base/network_change_notifier.h"
 
 namespace metrics {