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/StatsLogProcessor.h b/cmds/statsd/src/StatsLogProcessor.h
index 6178a4b..2c8382d 100644
--- a/cmds/statsd/src/StatsLogProcessor.h
+++ b/cmds/statsd/src/StatsLogProcessor.h
@@ -89,11 +89,11 @@
     void WriteDataToDisk(const DumpReportReason dumpReportReason,
                          const DumpLatency dumpLatency);
 
-    /* Persist metric activation status onto disk. */
-    void WriteMetricsActivationToDisk(int64_t currentTimeNs);
+    /* Persist configs containing metrics with active activations to disk. */
+    void SaveActiveConfigsToDisk(int64_t currentTimeNs);
 
-    /* Load metric activation status from disk. */
-    void LoadMetricsActivationFromDisk();
+    /* Load configs containing metrics with active activations from disk. */
+    void LoadActiveConfigsFromDisk();
 
     // Reset all configs.
     void resetConfigs();
@@ -221,6 +221,7 @@
     FRIEND_TEST(StatsLogProcessorTest, TestDropWhenByteSizeTooLarge);
     FRIEND_TEST(StatsLogProcessorTest, TestActiveConfigMetricDiskWriteRead);
     FRIEND_TEST(StatsLogProcessorTest, TestActivationOnBoot);
+    FRIEND_TEST(StatsLogProcessorTest, TestActivationOnBootMultipleActivations);
 
     FRIEND_TEST(WakelockDurationE2eTest, TestAggregatedPredicateDimensionsForSumDuration1);
     FRIEND_TEST(WakelockDurationE2eTest, TestAggregatedPredicateDimensionsForSumDuration2);