SoftAAC2: fix crash on all-zero adts buffer

Bug: 29153599
Change-Id: I1cb81c054098b86cf24f024f8479909ca7bc85a6

android::SoftOMXComponent *createSoftOMXComponent(
 const char *name, const OMX_CALLBACKTYPE *callbacks,
        OMX_PTR appData, OMX_COMPONENTTYPE **component) {
 return new android::SoftAAC2(name, callbacks, appData, component);
}

android::SoftOMXComponent *createSoftOMXComponent(
 const char *name, const OMX_CALLBACKTYPE *callbacks,
        OMX_PTR appData, OMX_COMPONENTTYPE **component) {
 return new android::SoftAAC2(name, callbacks, appData, component);
}
