[scripts] Add script to print clang prebuilts version

Bug: http://b/187231324

This script parses soong/cc/config/global.go to return clang prebuilts
version.  (It may get the version from a json config file in the
future.)

Currently it's used in development/scripts/symbol.py and is the
recommended way to get clang prebuilts version number in the future.

Test: get_clang_version_test.py
Change-Id: Id92a74fd523a5270999bb4d6454525bf2f2f0c04

scripts/get_clang_version_test.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2021 The Android Open Source Project
+#
+# 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.
+#
+"""Unit tests for get_clang_version.py."""
+
+import unittest
+
+import get_clang_version
+
+class GetClangVersionTest(unittest.TestCase):
+  """Unit tests for get_clang_version."""
+
+  def test_get_clang_version(self):
+    """Test parsing of clang prebuilts version."""
+    self.assertIsNotNone(get_clang_version.get_clang_prebuilts_version())
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)