aac: set initial timestamp to zero

Bug: 127405861
Test: bug repro steps
Change-Id: Id080eeb2345c19651329da3a6b7d7928a9aa3463
(cherry picked from commit 552e94c00308a56d8421caa5d8db40977ff02f86)
diff --git a/media/codecs/aac/C2SoftAacEnc.cpp b/media/codecs/aac/C2SoftAacEnc.cpp
index ea72aad..a963de7 100644
--- a/media/codecs/aac/C2SoftAacEnc.cpp
+++ b/media/codecs/aac/C2SoftAacEnc.cpp
@@ -153,7 +153,7 @@
       mSentCodecSpecificData(false),
       mInputTimeSet(false),
       mInputSize(0),
-      mInputTimeUs(-1ll),
+      mInputTimeUs(0),
       mSignalledError(false),
       mOutIndex(0u) {
 }
@@ -179,7 +179,7 @@
     mSentCodecSpecificData = false;
     mInputTimeSet = false;
     mInputSize = 0u;
-    mInputTimeUs = -1ll;
+    mInputTimeUs = 0;
     mSignalledError = false;
     return C2_OK;
 }
@@ -197,6 +197,7 @@
     mSentCodecSpecificData = false;
     mInputTimeSet = false;
     mInputSize = 0u;
+    mInputTimeUs = 0;
     return C2_OK;
 }
 
@@ -546,6 +547,7 @@
     mSentCodecSpecificData = false;
     mInputTimeSet = false;
     mInputSize = 0u;
+    mInputTimeUs = 0;
 
     // TODO: we don't have any pending work at this time to drain.
     return C2_OK;