MediaMetrics: Update Item serialization code

Add for bounds checking errors
Update key checks to omit length, use C primitive types

Test: atest mediametrics_tests, adb shell dumpsys media.metrics
Change-Id: I1e6d5bd7a9611f6d59e15a1dbebc646405e5a018
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
index 95c973a..4d9872a 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerDriver.cpp
@@ -641,7 +641,7 @@
             mAnalyticsItem->setUid(mClientUid);
         }
     } else {
-        ALOGV("nothing to record (only %d fields)", mAnalyticsItem->count());
+        ALOGV("nothing to record (only %zu fields)", mAnalyticsItem->count());
     }
 }