Bug: ol map not usable with Firefox on Android

[lbesson]

Describe the bug
Touching the map has no effect (and prevents scrolling the page)

Expected behavior
Pan / zoom the map

[lbesson]

ol was updated from 6.3.1 to 6.4.1
Version 6.4.0 removed pointer events polyfill
Pointer events are not supported by Firefox for Android (they should be at some point, since nightly works)