Initial implementation of layoutlib SBOM generation.

1) Build/dist build.prop, resource files
2) Generate layoutlib SBOM that includes build.prop, resource files,
   font files and font configuration files
3) Generate SBOM of framework_res.jar with placeholders for substitution
   in release_layoutlib.sh

Bug: 303903787
Bug: 303904046
Bug: 303904808
Bug: 303905932
Bug: 303906000
Bug: 303906275
Test: lunch sdk_phone64_arm64-userdebug && m layoutlib dist
Change-Id: Ib004e199e740ccc901e93b11201db2477464be1d
diff --git a/tools/sbom/generate-sbom-framework_res.py b/tools/sbom/generate-sbom-framework_res.py
new file mode 100644
index 0000000..d6be734
--- /dev/null
+++ b/tools/sbom/generate-sbom-framework_res.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 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.
+
+import argparse
+import hashlib
+import json
+import sbom_data
+import sbom_writers
+
+
+def get_args():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('-v', '--verbose', action='store_true', default=False,
+                      help='Print more information.')
+  parser.add_argument('--output_file', required=True,
+                      help='The generated SBOM file in SPDX format.')
+  parser.add_argument('--layoutlib_sbom', required=True,
+                      help='The file path of the SBOM of layoutlib.')
+
+  return parser.parse_args()
+
+
+def main():
+  global args
+  args = get_args()
+
+  doc = sbom_data.Document(name='<name>',
+                           namespace='<namespace>',
+                           creators=['Organization: <organization>'],
+                           created='<created>')
+
+  filename = 'data/framework_res.jar'
+  file_id = f'SPDXRef-{sbom_data.encode_for_spdxid(filename)}'
+  file = sbom_data.File(id=file_id, name=filename, checksum='SHA1: <checksum>')
+  doc.files.append(file)
+  doc.describes = file_id
+
+  with open(args.layoutlib_sbom, 'r', encoding='utf-8') as f:
+    layoutlib_sbom = json.load(f)
+
+  with open(args.layoutlib_sbom, 'rb') as f:
+    sha1 = hashlib.file_digest(f, 'sha1')
+
+  layoutlib_sbom_namespace = layoutlib_sbom[sbom_writers.PropNames.DOCUMENT_NAMESPACE]
+  external_doc_ref = 'DocumentRef-layoutlib'
+  doc.external_refs = [
+    sbom_data.DocumentExternalReference(external_doc_ref, layoutlib_sbom_namespace,
+                                        f'SHA1: {sha1.hexdigest()}')]
+
+  resource_file_spdxids = []
+  for file in layoutlib_sbom[sbom_writers.PropNames.FILES]:
+    if file[sbom_writers.PropNames.FILE_NAME].startswith('data/res/'):
+      resource_file_spdxids.append(file[sbom_writers.PropNames.SPDXID])
+
+  doc.relationships = []
+  for spdxid in resource_file_spdxids:
+    doc.relationships.append(
+      sbom_data.Relationship(file_id, sbom_data.RelationshipType.GENERATED_FROM,
+                             f'{external_doc_ref}:{spdxid}'))
+
+  # write sbom file
+  with open(args.output_file, 'w', encoding='utf-8') as f:
+    sbom_writers.JSONWriter.write(doc, f)
+
+
+if __name__ == '__main__':
+  main()