Screen Sharing button does not work on mobile platforms

[yedpodtrzitko]

Bug Description

mobile platforms are not fully supporting all features, one of them is screen sharing (see getMediaDisplay docs ), so displaying the toolbar button for screen sharing is pointless/misleading.

Expected behavior

one of the following:

• button for screen sharing won't be displayed when the platform does not support it
• button can be rendered (so the visible features are consistent across platforms to not cause user's confusion), but it will notice user about the platform limitation when used
• button can be rendered (so the visible features are consistent across platforms to not cause user's confusion), but will be disabled

more context

Following SO question shows that it's not possible to detect support of getMediaDisplay reliably, the proposed solution is to assume support via User Agent detection.