`mod procfs;` does not cover Android.

[TomJo2000]

Hi my name's Tom, I'm a package maintainer for the Termux project, which is a terminal app and packaging environment for Android 7+.

I ran into a complication with this crate while updating our starship package to version 1.25.0,
which now makes use of version 0.2.6 of systemstat.

The mod procfs; initially introduced in 512ec3c,

systemstat/src/platform/mod.rs

Lines 13 to 17 in 512ec3c

	#[cfg(any(
	target_os = "linux",
	target_os = "hurd",
	))]
	mod procfs;

stopped our package build from succeeding since it does not currently include target_os = "android" as a target with procfs support.

I was able to manually patch the cfg attribute to include android in the platform list to get it to compile, and it appears to be working as expected.
^{https://github.com/termux/termux-packages/blob/8fcca9e/packages/starship/systemstat-android-is-linux.diff}

It is very possible that Android doesn't work for the full extent of systemstat's procfs capabilities though, as starship makes very limited use of the systemstat crate, only using it in a single one of its modules.
^{https://github.com/starship/starship/blob/master/src/modules/memory_usage.rs}

[valpackett]

oh cool, I've used termux before! Yeah, I'll look into testing on android