Restored audio onStateChange log

Calls flushTsSeries when a state change was detected
to avoid logging idle audio time as a buffer period.

Test: dumpsys media.log
Change-Id: Ia33bec8829dcd5d2de5c40f904e5ea19c5a2b453
diff --git a/services/audioflinger/FastMixer.cpp b/services/audioflinger/FastMixer.cpp
index c4a0c0d..c10fa05 100644
--- a/services/audioflinger/FastMixer.cpp
+++ b/services/audioflinger/FastMixer.cpp
@@ -138,6 +138,8 @@
 
 void FastMixer::onStateChange()
 {
+    // log that audio was turned on/off
+    LOG_AUDIO_STATE();
     const FastMixerState * const current = (const FastMixerState *) mCurrent;
     const FastMixerState * const previous = (const FastMixerState *) mPrevious;
     FastMixerDumpState * const dumpState = (FastMixerDumpState *) mDumpState;