LLNDK version maps to NDK version

Instead of annotation duplicate LLNDK versions, use a corresponding
NDK version to find LLNDK symbols.
To generate LLNDK stubs, ndkstubgen sets `--llndk` argument with the
corresponding SDK version to its `--api` argument.

Bug: 361077712
Test: atest test_ndkstubgen
      atest test_symbolfile
Change-Id: I64cd6eaeae4451326bf2e74b4d2639933f004393
diff --git a/android/vendor_api_levels.go b/android/vendor_api_levels.go
new file mode 100644
index 0000000..4d364fd
--- /dev/null
+++ b/android/vendor_api_levels.go
@@ -0,0 +1,49 @@
+// Copyright 2024 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func getSdkVersionOfVendorApiLevel(apiLevel int) (int, bool) {
+	ok := true
+	sdkVersion := -1
+	switch apiLevel {
+	case 202404:
+		sdkVersion = 35
+	case 202504:
+		sdkVersion = 36
+	default:
+		ok = false
+	}
+	return sdkVersion, ok
+}
+
+func GetSdkVersionForVendorApiLevel(vendorApiLevel string) (ApiLevel, error) {
+	vendorApiLevelInt, err := strconv.Atoi(vendorApiLevel)
+	if err != nil {
+		return NoneApiLevel, fmt.Errorf("The vendor API level %q must be able to be parsed as an integer", vendorApiLevel)
+	}
+	if vendorApiLevelInt < 35 {
+		return uncheckedFinalApiLevel(vendorApiLevelInt), nil
+	}
+
+	if sdkInt, ok := getSdkVersionOfVendorApiLevel(vendorApiLevelInt); ok {
+		return uncheckedFinalApiLevel(sdkInt), nil
+	}
+	return NoneApiLevel, fmt.Errorf("Unknown vendor API level %q. Requires updating the map in vendor_api_level.go?", vendorApiLevel)
+}