Fixes for avb flags in soong-generated partitions

The logic for what variables control what aspect of AVB is pretty
complicated, this brings make and soong closer together.

Bug: 381120092
Test: m out/soong/.intermediates/build/soong/fsgen/aosp_cf_x86_64_phone_generated_system_image/android_common/prop, diff with make's prop file
Change-Id: I6ada90262f4578d120c35b7f8d38c06c2b1d9c27
diff --git a/scripts/text_file_processor.py b/scripts/text_file_processor.py
new file mode 100755
index 0000000..10186ce
--- /dev/null
+++ b/scripts/text_file_processor.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2024 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 re
+
+def main():
+    parser = argparse.ArgumentParser(description='This script looks for '
+        '`{CONTENTS_OF:path/to/file}` markers in the input file and replaces them with the actual '
+        'contents of that file, with leading/trailing whitespace stripped. The idea is that this '
+        'script could be extended to support more types of markers in the future.')
+    parser.add_argument('input')
+    parser.add_argument('output')
+    args = parser.parse_args()
+
+    with open(args.input, 'r') as f:
+        contents = f.read()
+
+    i = 0
+    replacedContents = ''
+    for m in re.finditer(r'{CONTENTS_OF:([a-zA-Z0-9 _/.-]+)}', contents):
+        replacedContents += contents[i:m.start()]
+        with open(m.group(1), 'r') as f:
+            replacedContents += f.read().strip()
+        i = m.end()
+    replacedContents += contents[i:]
+
+    with open(args.output, 'w') as f:
+        f.write(replacedContents)
+
+
+if __name__ == '__main__':
+    main()