Android support (#70)

### Motivation

This package wasn't building on Android, causing various dependent
packages to also fail to build.

### Modifications

Add the necessary `import(Android)` to successfully build.

### Result

The package can now be built for Android.

### Test Plan

~~Added CI to build and run against an Android emulator using
[swift-android-action](https://github.com/marketplace/actions/swift-android-action).~~

Author: marcprux

Sources/OpenAPIURLSession/BufferedStream/Lock.swift

@@ -28,6 +28,8 @@
 
 #if canImport(Darwin)
 import Darwin
+#elseif canImport(Android)
+import Android
 #elseif canImport(Glibc)
 import Glibc
 #elseif os(Windows)