Rename keystore.{h|cpp} to KeyStore.{h|cpp}

We currently have two different keystore.h files.  This renames one of
them, and the corresponding implementation, to KeyStore.h, which
tracks the class name.

Test: runtest --path cts/tests/tests/keystore/src/android/keystore/cts
Change-Id: I910e3d60d165b65d055e7da92acd04d3ee73a6d3
diff --git a/keystore/key_store_service.h b/keystore/key_store_service.h
index 81a0df1..0a1b8f1 100644
--- a/keystore/key_store_service.h
+++ b/keystore/key_store_service.h
@@ -21,7 +21,7 @@
 
 #include "auth_token_table.h"
 
-#include "keystore.h"
+#include "KeyStore.h"
 #include "keystore_keymaster_enforcement.h"
 #include "operation.h"
 #include "permissions.h"