Volume is wrongly computed for the Android TV component

[bogdanalexe90]

Home Assistant release with the issue:

Last working Home Assistant release (if known):

Operating environment (Hass.io/Docker/Windows/etc.):

Component/platform:

Description of problem:
The volume of the new Android TV component should be between 0 and 1. Ideally the max volume should be retrieved from the TV and the volume level should be computed based on that.

Problem-relevant configuration.yaml entries and (fill out even if it seems unimportant):

Traceback (if applicable):

Additional information:
JeffLIrion/python-androidtv#9