MediaMetrics: Fix clang-tidy warnings

Test: atest mediametrics_tests
Bug: 153658358
Change-Id: Ic3c05de5466df24ffd37b224c97ac1138257a73c
diff --git a/services/mediametrics/AudioAnalytics.cpp b/services/mediametrics/AudioAnalytics.cpp
index f80516e..3f9a42f 100644
--- a/services/mediametrics/AudioAnalytics.cpp
+++ b/services/mediametrics/AudioAnalytics.cpp
@@ -115,7 +115,7 @@
 
     if (ll > 0) {
         auto [s, l] = mAnalyticsState->dump(ll, sinceNs, prefix);
-        ss << std::move(s);
+        ss << s;
         ll -= l;
     }
     if (ll > 0) {
@@ -124,7 +124,7 @@
     }
     if (ll > 0) {
         auto [s, l] = mPreviousAnalyticsState->dump(ll, sinceNs, prefix);
-        ss << std::move(s);
+        ss << s;
         ll -= l;
     }
     return { ss.str(), lines - ll };