Protect mMicSamplingPeriodBackup by mConnectionLock

Test: Presubmit
Fixes: 357599979
Flag: EXEMPT bug fix
Change-Id: I705579eef8cc5fe371f3e57d0e16e8df1acfc3c5
diff --git a/services/sensorservice/Android.bp b/services/sensorservice/Android.bp
index f4b0265..7b2596a 100644
--- a/services/sensorservice/Android.bp
+++ b/services/sensorservice/Android.bp
@@ -52,6 +52,7 @@
         "-Wall",
         "-Werror",
         "-Wextra",
+        "-Wthread-safety",
         "-fvisibility=hidden",
     ],