Save EventActivations to disk

Also:
- rename time_to_live to ttl
- rename activation_ns to start_ns

Bug: 129719662
Fixes: 129719662
Test: statsd_test

Change-Id: I4069f85d0c1f5bd0885a9588d8a9157d94b2c587
diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index 4c97c34..662be05 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -986,7 +986,7 @@
     ENFORCE_UID(AID_SYSTEM);
     VLOG("StatsService::informDeviceShutdown");
     mProcessor->WriteDataToDisk(DEVICE_SHUTDOWN, FAST);
-    mProcessor->WriteMetricsActivationToDisk(getElapsedRealtimeNs());
+    mProcessor->SaveActiveConfigsToDisk(getElapsedRealtimeNs());
     return Status::ok();
 }
 
@@ -1021,14 +1021,14 @@
 
 void StatsService::Startup() {
     mConfigManager->Startup();
-    mProcessor->LoadMetricsActivationFromDisk();
+    mProcessor->LoadActiveConfigsFromDisk();
 }
 
 void StatsService::Terminate() {
     ALOGI("StatsService::Terminating");
     if (mProcessor != nullptr) {
         mProcessor->WriteDataToDisk(TERMINATION_SIGNAL_RECEIVED, FAST);
-        mProcessor->WriteMetricsActivationToDisk(getElapsedRealtimeNs());
+        mProcessor->SaveActiveConfigsToDisk(getElapsedRealtimeNs());
     }
 }