Rename OUT_OF_KEYS -> OUT_OF_KEYS_TRANSIENT

More OUT_OF_KEYS errors are coming, and the old "OUT_OF_KEYS" is a
bucket for all transient errors. Rename the enum to better indicate
this.

Also rename OUT_OF_KEYS_REQUIRES_UPGRADE to
OUT_OF_KEYS_REQUIRES_SECURITY_PATCH. This better indicates that
system is potentially vulnerable (rather than simply running old code).

Test: keystore2_test
Change-Id: I1f2d803529c3e43592536016a9261e2294b42bb5
diff --git a/keystore2/src/database.rs b/keystore2/src/database.rs
index 62fd579..f4333cd 100644
--- a/keystore2/src/database.rs
+++ b/keystore2/src/database.rs
@@ -1859,7 +1859,8 @@
                 let (_, hw_info) = get_keymint_dev_by_uuid(km_uuid)
                     .context("Error in retrieving keymint device by UUID.")?;
                 log_rkp_error_stats(MetricsRkpError::OUT_OF_KEYS, &hw_info.securityLevel);
-                return Err(KsError::Rc(ResponseCode::OUT_OF_KEYS)).context("Out of keys.");
+                return Err(KsError::Rc(ResponseCode::OUT_OF_KEYS_TRANSIENT_ERROR))
+                    .context("Out of keys.");
             } else if result > 1 {
                 return Err(KsError::sys())
                     .context(format!("Expected to update 1 entry, instead updated {}", result));