updater_sample: Add streaming to PayloadSpec

PayloadSpec
- add streaming generator and tests
- fix sample.json
- fix tests
- rename PackagePropertyFiles to PackageFiles, it has info
  not only about property files, and new name is shorter

Bug: 77148467
Test: `mmma -j bootable/recovery/updater_sample`
Change-Id: I9c1206c07c37183f13d3c25940f12981ca85b1b4
Signed-off-by: Zhomart Mukhamejanov <zhomart@google.com>
diff --git a/updater_sample/tests/res/raw/update_config_stream_001.json b/updater_sample/tests/res/raw/update_config_stream_001.json
index a9afd33..15127cf 100644
--- a/updater_sample/tests/res/raw/update_config_stream_001.json
+++ b/updater_sample/tests/res/raw/update_config_stream_001.json
@@ -6,8 +6,8 @@
         "property_files": [
             {
                 "filename": "payload.bin",
-                "offset": 531,
-                "size": 5012323
+                "offset": 195,
+                "size": 8
             }
         ]
     }