Carry attempt id through our test record reporting

Ensure we carry the attempt-id of the new interface through
the test record.

Test: unit tests
Bug: 112664318
Change-Id: Iad9f33c42b4c82336234ab805a285595f656a782
diff --git a/proto/test_record.proto b/proto/test_record.proto
index cd4fa36..cbbfafc 100644
--- a/proto/test_record.proto
+++ b/proto/test_record.proto
@@ -61,6 +61,10 @@
 
   // Metadata describing the test that was run.
   google.protobuf.Any description = 11;
+
+  // The attempt number of a target if the target ran several times. First
+  // attempt is 0 (Default value).
+  int64 attempt_id = 12;
 }
 
 // A reference to a finer-grained TestRecord.