Print gradle output on compiling

Enable the attribute "console" of custom_target() introduced in meson
0.48. This allows to get a feedback of what gradle does (which can takes
a very long time).

This produces warnings because we declare to support meson >= 0.37, but
we don't want to stop supporting older versions for that. Older versions
just ignore the option:

> WARNING: Unknown keyword arguments in target scrcpy-server: console

Newer meson versions use it, but warn because we declare supporting
older versions:

> WARNING: Project targetting '>= 0.37' but tried to use feature
> introduced in '0.48.0': console arg in custom_target

Meson does not support conditional branches to suppress such warnings,
so just keep the warnings.