api: ACTION_GET_KEY selects by any subkey, rather than just master key id

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/OpenPgpService.java

@@ -621,7 +621,8 @@ public class OpenPgpService extends Service {
             try {
                 // try to find key, throws NotFoundException if not in db!
                 CanonicalizedPublicKeyRing keyRing =
-                        mProviderHelper.getCanonicalizedPublicKeyRing(masterKeyId);
+                        mProviderHelper.getCanonicalizedPublicKeyRing(
+                                KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(masterKeyId));
 
                 Intent result = new Intent();
                 result.putExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_SUCCESS);