Fix/suppress statsd google-explicit-constructor warnings

* Add explicit to conversion constructors/operators
* Remove redundant explicit of copy constructors

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: Ifd0ca9a1afe4a2cb0456a36c69bee1633af5a93a
diff --git a/cmds/statsd/src/anomaly/AlarmMonitor.h b/cmds/statsd/src/anomaly/AlarmMonitor.h
index 3badb1f..bca858e 100644
--- a/cmds/statsd/src/anomaly/AlarmMonitor.h
+++ b/cmds/statsd/src/anomaly/AlarmMonitor.h
@@ -42,7 +42,7 @@
  * Timestamps are in seconds since epoch in a uint32, so will fail in year 2106.
  */
 struct InternalAlarm : public RefBase {
-    InternalAlarm(uint32_t timestampSec) : timestampSec(timestampSec) {
+    explicit InternalAlarm(uint32_t timestampSec) : timestampSec(timestampSec) {
     }
 
     const uint32_t timestampSec;