Set default value to mAttributes in AudioTrack

mAttributes in AudioTrack can not be set in AudioTrack::set()
when pAttributes is NULL.
AudioTrack::getPosition() sometimes returns wrong value
since mAttributes is undefined value.
This change sets default values to mAttributes.

Bug: 123607740
Test: manual
Change-Id: Ie590c17efc466cc89cbd7e9f89fc3ebeed98eace

media/libaudioclient/AudioTrack.cpp

@@ -282,6 +282,11 @@ AudioTrack::AudioTrack(
       mPreviousSchedulingGroup(SP_DEFAULT),
       mPausedPosition(0)
 {
+    mAttributes.content_type = AUDIO_CONTENT_TYPE_UNKNOWN;
+    mAttributes.usage = AUDIO_USAGE_UNKNOWN;
+    mAttributes.flags = 0x0;
+    strcpy(mAttributes.tags, "");
+
     (void)set(streamType, sampleRate, format, channelMask,
             frameCount, flags, cbf, user, notificationFrames,
             0 /*sharedBuffer*/, false /*threadCanCallJava*/, sessionId, transferType,
@@ -313,6 +318,11 @@ AudioTrack::AudioTrack(
       mPausedPosition(0),
       mSelectedDeviceId(AUDIO_PORT_HANDLE_NONE)
 {
+    mAttributes.content_type = AUDIO_CONTENT_TYPE_UNKNOWN;
+    mAttributes.usage = AUDIO_USAGE_UNKNOWN;
+    mAttributes.flags = 0x0;
+    strcpy(mAttributes.tags, "");
+
     (void)set(streamType, sampleRate, format, channelMask,
             0 /*frameCount*/, flags, cbf, user, notificationFrames,
             sharedBuffer, false /*threadCanCallJava*/, sessionId, transferType, offloadInfo,