Do not convert java libraries with core_platform

Test: go bp2build tests
Change-Id: I2769c0d589c304caeb24a8ecba38a4a5ee6c63e5
diff --git a/bp2build/java_library_conversion_test.go b/bp2build/java_library_conversion_test.go
index 7429ae6..9908691 100644
--- a/bp2build/java_library_conversion_test.go
+++ b/bp2build/java_library_conversion_test.go
@@ -1046,3 +1046,14 @@
 		ctx.RegisterModuleType("filegroup", android.FileGroupFactory)
 	})
 }
+
+func TestJavaSdkVersionCorePlatformDoesNotConvert(t *testing.T) {
+	runJavaLibraryTestCase(t, Bp2buildTestCase{
+		Blueprint: `java_library {
+    name: "java-lib-1",
+    sdk_version: "core_platform",
+    bazel_module: { bp2build_available: true },
+}`,
+		ExpectedBazelTargets: []string{},
+	})
+}
diff --git a/java/java.go b/java/java.go
index 521aef3..967f8c2 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2904,8 +2904,13 @@
 	var staticDeps bazel.LabelListAttribute
 
 	if proptools.String(m.deviceProperties.Sdk_version) == "" && m.DeviceSupported() {
+		// TODO(b/297356704): handle platform apis in bp2build
 		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_PROPERTY_UNSUPPORTED, "sdk_version unset")
 		return &javaCommonAttributes{}, &bp2BuildJavaInfo{}, false
+	} else if proptools.String(m.deviceProperties.Sdk_version) == "core_platform" {
+		// TODO(b/297356582): handle core_platform in bp2build
+		ctx.MarkBp2buildUnconvertible(bp2build_metrics_proto.UnconvertedReasonType_PROPERTY_UNSUPPORTED, "sdk_version core_platform")
+		return &javaCommonAttributes{}, &bp2BuildJavaInfo{}, false
 	}
 
 	archVariantProps := m.GetArchVariantProperties(ctx, &CommonProperties{})