Import the Android module if available, since glibc and musl are unavailable on Android (#198)

I don't expect us to run CI against this until that's more formally
supported, but this would greatly help adoption of server-focused
packages on Android

Author: Joannis

Sources/ConcurrencyHelpers/Lock.swift

@@ -35,6 +35,8 @@ import WinSDK
 import Glibc
 #elseif canImport(Musl)
 import Musl
+#elseif canImport(Android)
+import Android
 #endif
 
 #if os(Windows)

Sources/UnixSignals/UnixSignal.swift

@@ -18,6 +18,8 @@ import Darwin
 import Glibc
 #elseif canImport(Musl)
 import Musl
+#elseif canImport(Android)
+import Android
 #endif
 import Dispatch
 

Sources/UnixSignals/UnixSignalsSequence.swift

@@ -21,6 +21,9 @@ import Glibc
 #elseif canImport(Musl)
 @preconcurrency import Dispatch
 import Musl
+#elseif canImport(Android)
+@preconcurrency import Dispatch
+import Android
 #endif
 import ConcurrencyHelpers
 

Tests/UnixSignalsTests/UnixSignalTests.swift

@@ -20,6 +20,8 @@ import Darwin
 import Glibc
 #elseif canImport(Musl)
 import Musl
+#elseif canImport(Android)
+import Android
 #endif
 
 final class UnixSignalTests: XCTestCase {