Bump oat version after compiler filter name changes.

bug:37988580
Test: build

(cherry picked from commit f977691961b5a49a074a535fcb29a5ad4a318974)

Change-Id: If52e569b6403a8b3f2e31d472b6d11ab42d13763
diff --git a/runtime/oat.h b/runtime/oat.h
index 05706252..a38eebc 100644
--- a/runtime/oat.h
+++ b/runtime/oat.h
@@ -32,7 +32,7 @@
 class PACKED(4) OatHeader {
  public:
   static constexpr uint8_t kOatMagic[] = { 'o', 'a', 't', '\n' };
-  static constexpr uint8_t kOatVersion[] = { '1', '1', '9', '\0' };  // Add thread_local_limit.
+  static constexpr uint8_t kOatVersion[] = { '1', '2', '4', '\0' };  // New compiler filter names.
 
   static constexpr const char* kImageLocationKey = "image-location";
   static constexpr const char* kDex2OatCmdLineKey = "dex2oat-cmdline";