Some cleanups to recovery.

- Remove the duplicate gCurrentUI variable in recovery.cpp;
- Refactor the load/save of locale functions;
- Clean up ui_print() to get rid of 256-byte buffer limit;
- Declare ui in common.h;
- Move the typedef of Volume into roots.h.

Test: Build and boot into recovery image.

Change-Id: Ia28c116858ca754133127a5ff9c722af67ad55b7

verifier.cpp

@@ -14,9 +14,11 @@
  * limitations under the License.
  */
 
+#include "verifier.h"
+
 #include <errno.h>
-#include <malloc.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <algorithm>
@@ -31,9 +33,6 @@
 #include "common.h"
 #include "print_sha1.h"
 #include "ui.h"
-#include "verifier.h"
-
-extern RecoveryUI* ui;
 
 static constexpr size_t MiB = 1024 * 1024;