Rust cdylib/statliclib support for vendor snapshot.

Adds support for platform vendor_available Rust FFI libraries and
binaries to be included in the vendor snapshot.

Because rlib and dylibs are not yet in snapshots, libstd cannot be
included in a vendor snapshot. As a result, vendor-specific Rust code
can't be guaranteed to work with the platform-provided vendor_available
modules built with a newer toolchain. For now, a check is added
indicating vendor-specific Rust code is unsupported.

This changes the linkage for vendor variants of these modules to default
to rlib linkage since dylibs cannot be included in the snapshot yet.

Bug: 184042776
Test: m nothing # new Soong tests pass
Change-Id: I502eaa4bb962eb87ff868fcf49b435f0d2f982e6
diff --git a/rust/rust_test.go b/rust/rust_test.go
index 6ae05d9..f07f86b 100644
--- a/rust/rust_test.go
+++ b/rust/rust_test.go
@@ -37,21 +37,28 @@
 
 	genrule.PrepareForTestWithGenRuleBuildComponents,
 
-	PrepareForIntegrationTestWithRust,
+	PrepareForTestWithRustIncludeVndk,
+	android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+		variables.DeviceVndkVersion = StringPtr("current")
+		variables.ProductVndkVersion = StringPtr("current")
+		variables.Platform_vndk_version = StringPtr("29")
+	}),
 )
 
 var rustMockedFiles = android.MockFS{
-	"foo.rs":          nil,
-	"foo.c":           nil,
-	"src/bar.rs":      nil,
-	"src/any.h":       nil,
-	"proto.proto":     nil,
-	"proto/buf.proto": nil,
-	"buf.proto":       nil,
-	"foo.proto":       nil,
-	"liby.so":         nil,
-	"libz.so":         nil,
-	"data.txt":        nil,
+	"foo.rs":                       nil,
+	"foo.c":                        nil,
+	"src/bar.rs":                   nil,
+	"src/any.h":                    nil,
+	"c_includes/c_header.h":        nil,
+	"rust_includes/rust_headers.h": nil,
+	"proto.proto":                  nil,
+	"proto/buf.proto":              nil,
+	"buf.proto":                    nil,
+	"foo.proto":                    nil,
+	"liby.so":                      nil,
+	"libz.so":                      nil,
+	"data.txt":                     nil,
 }
 
 // testRust returns a TestContext in which a basic environment has been setup.
@@ -67,10 +74,16 @@
 }
 
 func testRustVndk(t *testing.T, bp string) *android.TestContext {
+	return testRustVndkFs(t, bp, rustMockedFiles)
+}
+
+const vendorVariant = "android_vendor.29_arm64_armv8-a_shared"
+
+func testRustVndkFs(t *testing.T, bp string, fs android.MockFS) *android.TestContext {
 	skipTestIfOsNotSupported(t)
 	result := android.GroupFixturePreparers(
 		prepareForRustTest,
-		rustMockedFiles.AddToFixture(),
+		fs.AddToFixture(),
 		android.FixtureModifyProductVariables(
 			func(variables android.FixtureProductVariables) {
 				variables.DeviceVndkVersion = StringPtr("current")
@@ -80,6 +93,7 @@
 		),
 	).RunTestWithBp(t, bp)
 	return result.TestContext
+
 }
 
 // testRustCov returns a TestContext in which a basic environment has been
@@ -115,10 +129,14 @@
 
 // testRustVndkError is similar to testRustError, but can be used to test VNDK-related errors.
 func testRustVndkError(t *testing.T, pattern string, bp string) {
+	testRustVndkFsError(t, pattern, bp, rustMockedFiles)
+}
+
+func testRustVndkFsError(t *testing.T, pattern string, bp string, fs android.MockFS) {
 	skipTestIfOsNotSupported(t)
 	android.GroupFixturePreparers(
 		prepareForRustTest,
-		rustMockedFiles.AddToFixture(),
+		fs.AddToFixture(),
 		android.FixtureModifyProductVariables(
 			func(variables android.FixtureProductVariables) {
 				variables.DeviceVndkVersion = StringPtr("current")