Add config to control full task snapshot scale

- Also save the scale with the snapshot data instead of trying to infer it
  from the state
- Also recycle the reduced resolution snapshot copy after writing it

Bug: 135150767
Test: atest TaskSnapshotPersisterLoaderTest
Change-Id: I64a9ccf16f3966ad5c6d07ff0b6ce8e9dd710e40
diff --git a/proto/src/task_snapshot.proto b/proto/src/task_snapshot.proto
index a1bbe52..381d983 100644
--- a/proto/src/task_snapshot.proto
+++ b/proto/src/task_snapshot.proto
@@ -32,4 +32,5 @@
      int32 system_ui_visibility = 8;
      bool is_translucent = 9;
      string top_activity_component = 10;
+     float scale = 11;
  }
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