Fix initialization of AAC presentation struct

Otherwise the new size checks trip on this.

Bug: 27207275
Change-Id: I1f8f01097e3a88ff041b69279a6121be842f1766

size_t ACodec::PortDescription::countBuffers() {
 return mBufferIDs.size();
}

size_t ACodec::PortDescription::countBuffers() {
 return mBufferIDs.size();
}
