Enhance Security Logs for Clarity

Addressing numerous reports regarding
the output from the security_level file,
this update improves the logs and resolves
previous bugs.

Test: atest keystore2_test
Test: atest CtsKeystoreTestCases
Change-Id: I682c384383a39df4ee291c49500907e65d9e59aa
diff --git a/keystore2/src/legacy_importer.rs b/keystore2/src/legacy_importer.rs
index f9d5d1b..045f848 100644
--- a/keystore2/src/legacy_importer.rs
+++ b/keystore2/src/legacy_importer.rs
@@ -928,6 +928,6 @@
         },
         |_| Ok(()),
     )
-    .context(ks_err!("Key blob upgrade failed, possibly invalid keyblob for uuid {uuid:?}"))?;
+    .context(ks_err!("getKeyCharacteristics failed: possibly invalid keyblob for uuid {uuid:?}"))?;
     Ok((key_characteristics_to_internal(characteristics), upgraded_blob))
 }