Revert^2 "keystore2: cope with new curve25519 enum"

6c44cad429721ebaf2216d412aa7f9417936cd70

Change-Id: Ib0c57111991221d6117cf2e5e2e9af0a13ce167e
diff --git a/keystore2/src/metrics_store.rs b/keystore2/src/metrics_store.rs
index 741d65e..0b29b25 100644
--- a/keystore2/src/metrics_store.rs
+++ b/keystore2/src/metrics_store.rs
@@ -287,6 +287,7 @@
                     EcCurve::P_256 => MetricsEcCurve::P_256,
                     EcCurve::P_384 => MetricsEcCurve::P_384,
                     EcCurve::P_521 => MetricsEcCurve::P_521,
+                    EcCurve::CURVE_25519 => MetricsEcCurve::CURVE_25519,
                     _ => MetricsEcCurve::EC_CURVE_UNSPECIFIED,
                 }
             }