Prefer the overload of getDigestAlgorithm spelled correctly.

Change-Id: Iaf1c031b982890c2ef21607bdf80acd652646e19
diff --git a/core/java/android/os/RecoverySystem.java b/core/java/android/os/RecoverySystem.java
index 6d19f41..4991914 100644
--- a/core/java/android/os/RecoverySystem.java
+++ b/core/java/android/os/RecoverySystem.java
@@ -244,7 +244,7 @@
             // algorithm is used by the signature (which should be
             // SHA1withRSA).
 
-            String da = sigInfo.getdigestAlgorithm();
+            String da = sigInfo.getDigestAlgorithm();
             String dea = sigInfo.getDigestEncryptionAlgorithm();
             String alg = null;
             if (da == null || dea == null) {