The main problem is with the z-index of the .modal
Use this,
.ui-autocomplete {
z-index: 1051 !important;
}
(or)
.pac-container {
background-color: #FFF;
z-index: 20;
position: fixed;
display: inline-block;
float: left;
}
.modal{
z-index: 20;
}
.modal-backdrop{
z-index: 10;
}