Replace non-alphanumerics with _ in VirtualKeyMap

We currently rewrite device name for finding the matching .idc, .kl,
.kcm files, but we aren't allowing this for virtual key maps.

Rewrite the name for virtual devices to provide some flexibility in
matching for the right files in sys/board_properties.

Bug: 113575658
Test: atest libinput_tests inputflinger_tests
Change-Id: I54d159e9ecf02327cae388ae14c0bcf21c415e6e