Disable all SDK snapshot generation tests on mac.

We frequently miss putting in the per-test skip condition, and since
mac isn't tested in presubmit this leads to build breakages and time
consuming reverts. To avoid that this blanket disables all the SDK
tests on mac. It's not used there and we got test coverage in many
linux-based builds.

Bug: 145598135
Bug: 161315642
Test: `go test -v ./sdk` in build/soong on mac and linux
Change-Id: I2aea92fef2c0f8c2742396fe36610501dc5a6f0f

sdk/sdk_test.go

@@ -15,6 +15,9 @@
 package sdk
 
 import (
+	"android/soong/android"
+	"log"
+	"os"
 	"testing"
 
 	"github.com/google/blueprint/proptools"
@@ -22,6 +25,12 @@ import (
 
 // Needed in an _test.go file in this package to ensure tests run correctly, particularly in IDE.
 func TestMain(m *testing.M) {
+	if android.BuildOs != android.Linux {
+		// b/145598135 - Generating host snapshots for anything other than linux is not supported.
+		log.Printf("Skipping as sdk snapshot generation is only supported on %s not %s", android.Linux, android.BuildOs)
+		os.Exit(0)
+	}
+
 	runTestWithBuildDir(m)
 }